[Thumpin455_GTO]

Lets say you wanted to make max power but have it look completely stock, down to the airfilter, heads, intake, etc. Anything goes inside, and possibly use an aftermarket block but preferably a stock 400 or 455 block. Using RA type manifolds. D port or HO heads, since we cant afford SD heads and RA IV is too much compression.

It has to run on pump gas, only an iron head, no E's, KRE, or Tigers. Think of it as a super stock engine that will run on 87 octane.

Chassis would be a 70-72 A body that is lightened by also stock looking from 10 feet away. Th350 and streetable gears (3.08-3.73). Around 2800-3100lbs.

It would be set up so when you open the hood, it looks like a 350 with a Qjet on it. Could possibly have nitrous plumbed under the intake, but dont want to rely on happy gas.

Doesnt have to fit any rules, such as F.A.S.T. or stock/super stock. Just a sleeper for a bit of fun.. What would you build?

[Brian Baker]

Either a stroker 400 (4.25" crank with a 4.151" bore) or a 440" based on a 428 with aluminum rods and forged pistons.

Race ported d-ports yielding 10:1 CR (take your pick)...run 92 octane gas.

Edelbrock Torker-II intake (nobody will pay much attention to it with a Q-Jet sitting on it).

Worked over Q-Jet.

2.5" aftermarket ram-air exhaust manifolds that have been extrude honed.

Solid roller cam in the 270-280 @ .050" range, 110-lda.

Ditch the th350 and install a th400, with a tight 10" nitrous convertor. 3.73 rear gears.

Hide the nitrous plumbing into the manifold. With a 200-HP shot of nitrous, and some chassis tuning, a 3500 lb. car should see 9.90's in the 1/4 mile (or better).

Hide the fuel regulator and maybe run the plumbing through a "dummy" stock fuel pump (no guts, just there to look factory).

[MrPushrod]

Two stages hiding in my air cleaner.

[75TA]

Thumpin455_GTO

You would not be able to use current aftermarket blocks as you can tell the difference very quickly. The aftermarket blocks are much more beefy to where on the driver side the block sticks out about an inch past the head at the front (stock block is flush). Additionally, the block sticks out past the heads on the sides (stock block is flush).

[Will]

I agree with Brian except that I think a 112 LDA would work better as it is more forgiving of exhaust restriction and less than optimum header primary length (which is what you're faced with using RA manifolds), and it'll work a little better with the nitrous too.

There are head porters out there who know how to get 290+ CFM from iron heads. Use whatever castings they recommend then select a piston with a dish to get the CR you want.

[lugnutt]

I think I would put a low compression 540 together, with a mild cam wide lobe center. It would make gobs of torque., and sound mild.
Make it look ugly with rust, and grease. I dont think most people would pay that close attention to an old pontiac!! Until it blew by em!!!
Then if you wanted to turn it up later, install a procharger. Cause once you get the bug.................

[Elarson]

I ran a sleeper 455-HO car many years ago, so this is a fun topic for me. I basically agree with the things already suggested. Most important in my mind (sorta in order)

1) biggest cubes you can afford
2) roller cam (for great breathing w/o killing low end torque)
3) free-flowing exhaust...dual 3" as a minimum
4) that 3.73 gear you mentioned
5) 455-HO/RAIV aluminum intake with Q-jet & blocked exhaust crossover
6) head porting

[Brian Baker]

Also, I forgot to add that race filling the block would be a must. In my opinion just filling the water jackets to the bottom or halfway across the freeze plugs is not enough. Fill it to at least the bottom of the water pump holes.

[mchell]

I am running low 12's with an absolutely stock looking engine and a race weight of 3965lbs.

10/1 compression
#96 heads milled to 82cc and flowing 245 at .500 lift
239/244 hydraulic cam
1.6 roller rockers
stock intake
Qjet
RA/HO manifolds
2 1/2 inch exhaust with x and dumps
stock crank
stock block
eagle rods
BRC pistons
3.90 cogs
3965lbs race weight

With your proposed weight you should be able to run low 11's maybe high 10's with the right combo...............that would be a SWEET sleeper.......very fast........of course you could do like the fast class guy's and run 14 to 1 compression and hog out and smooth out every orfice.......who knows what you could run at that weight???? Running $5.00 or more for a gallon of gas could limit your fun factor.....

[mchell]

forgot to add......its a 463

[Skip Fix]

The HO 455 heads might be something to look at also. Good flow can mill down for more compression or use a mini dome.

If long brach manifolds could be made to fit they flow better then HOs. I think RARE even makes them with 3" exits.

[screamingchief]

I'm thinking max cubes:
SD 455 block (yeah rare/pricey I know,but you were mentioning aftermarket soooo).
Filled to freeze plug,billet caps on all mains except rear main likely,full "prep".
Sonic check and bore to within an inch of it's life 4.21" for sure,4.25" if the meat is there.

Billet 4.5" stroke crank,BBC or maybe SBC journals.

Rods,as long as practical and still have a decent ring package,get 'em as light as possible for the material chosen (likely aluminum).

Best pistons I could afford,built to fit combo,as light as possible but still sturdy enough for some occasional nitrous use,but not a whole bunch of spray,250 shot max likely.

Use only high quality rings and bearings,pretty much standard stuff though.

And consider using "hi-tech" coatings throughout the engine.

Heads,well you ruled out the RAIV and SD heads,so I gotta say use the '71 455 H-O heads,casting #197,these have a little better exhaust ports than the '72 7F6 H-O heads according to the pontiac "lore" IIRC.

Mill the heads to get the CC's down around 100 CC's,Standard "full on" prep,fill the crossovers,slot the pushrod slots,then port these to suckers to the max!

Cometic gaskets,and a fresh set of OE headbolts,the ARP bolts or studs would likely be a giveaway IMO.

Solid roller is a natural,and the added lifter bore bracing of the SD block will help here,I would'nt go too crazy though,this engine will make tons of power,so you really should'nt need to go too big,durations @ .050" in the mid 260in./270exh.,.406 lobes,112 LSA installed around 106 ICL.

Use the crower HIPPO rollers and good springs and titanium retainers.

And I'd use some shaft mount rocker assemblies,this way you wont need the stud girdles and you stand a better chance of getting it all to fit under a stock "ish" valve-cover using a minimum of "tricks" that would give away the deception,use a higher ratio rocker to get the added lift vs. the "lobe" lift of the cam,I'd likely use a 1.65 ratio with the .406" lobes myself.

Use the Simms thrust plate/rollmaster set for timing chain duties.

MSD distributor in disguise,black super-conductor 8.5 wires.

I agree I'd likely use an aftermarket intake,but I would grind off any "brand" logos and paint it,I would probably use an RPM if I wanted to keep it a dual plane and use a Q-jet,skeletonize it ala' the H-O intakes and I'd doubt all but the most savvy would recognize it as anything other than a stocker,especially "sans logos" and painted.

Use the H-O block off plates to make it appear more like the OE H-O manifold sans crossover.

If need be too,weld the ports to fit the heads,grind carefully to maintain the "stock" appearence of the intake.

Cut down the divider in the RPM,and fit an in plenum spray bar if practical,otherwise cleverly diguise the nitrous plate under a carb "heatshield" and disguise the lines and solenoids as SOP.

The exhaust is the b!tch on this deal for sure,yeah,use the "big" opening RA manifolds and extrude hone as much as you'd feel safe doing,definately you need as big a pipe as you can make work,use every exhaust "trick" in the book,and maybe invent a few more...

Oiling,well,use the standard/prep/hardware inside,blueprinted/prepped pump,shim for pressure (appx.70psi),billet driveshaft,disguise a canton pan as best as possible,paint to match the engine,use a scrapper,and use Ace's new H-D tray likely too,pretty much whatever has worked for ya'll in the past.

I'd have to use a "dummy" mechanical fuel pump to maintain the subterfuge.

And keep all the stock external hardware,use an aluminum waterpump with the good impeller,and gap the divider per SOP,stock pulleys,brackets etc..

I'm sure I left a thing or two out,but you get the idea,pretty much the same as a few of the others here,built right it should be a handful.

Easy tens on motor,and easy nines on spray IMO.

Better have a good chassis,that'll likely be a bigger "give-away" than the engine would ever be...

And be ready to get booted from the track for the "missing" saftey equipment that a true sleeper would never have,as that is another dead give-away!

BTW,I think a TH-350 will be hard pressed to live long behind a combo like this,I would go with either a th-400 or glide,JMO,not saying it's not possible to build a pretty stout th-350,but this type of build will be real hard on any trans.

Bret.

[goquick]

SC's ideas are right on. You would be very hard pressed to beat a combo like that.

[Thumpin455_GTO]

Kinda what I was thinkin myself.. I figure if its going against chevy guys, they dont know the difference in most of our parts anyway. Hence the aftermarket block. Wont pass by a Pontiac knowledgable guy, but a chevy guy likely wont notice at all.

The HO heads stand out since D ports arent mandatory. Could run headers and most people wouldnt think much of it, but just letting people look and they only see iron manifolds could get a few lengths..

The chassis in my mind is a 71 T37 that i got from a junkyard back in 85 for $175. Since it needs a front end, fiberglass is the obvious choice. Using the inner fender support that the hood bolts to as the upper mount would allow a bolt on hood and look like a stock fender. Run fender wells so you cant see through to the engine, and its believable. Someone on here has already done it, so its possible. I have a 70 LeMans header panel and can get a glass LM bumper so stock headlights will work. Add glass doors with street rod style electric lifts and possibly speed glass instead of lexan. Yes it would take bracing and engineering but its possible.

Leave absolutely nothing under the dash, but have a fake heater hose going to the firewall. Maybe even the AC doghouse under the hood with nothing in it. Bench seat, column shifter, manual brakes/steering, no sound deadener under a carpet, and run a headliner so it looks like a full interior with a back seat. Could possibly swiss cheese the inner structures under the kick panels and the cowl area. No radio, maybe just a gutted face of a stock AM.

If painted, a sleepy color or maybe the factory lucerne blue. (easiest choice) or black/grey primer. Paint the bumpers body color since they are glass front and rear. Maybe run a stock rear since the weight back there might help a bit. so it looks like a grandma car from the outside. section a stock fuel tank and use the bottom half with a fuel cell inside. Hide the pump, regulator and other bits inside the factory tank.

Camoflaged 9" rear with a 10 bolt cover welded to the back. Have it sit low enough you need a jack to see much of the rear end, that will also help with the wheel hop. Stock 15x7 or 15x8 Rally IIs sans trim rings, and add a couple "racer stickers" like cherry bombs or some other crap.

Enough taken out of it and light engine parts like the aluminum rods/intake could get it down around the target weight. 2900 with me in it would be nice. But that would be a 2650lb car empty. So yeah. gotta get creative if its going to be anywhere near that light and look anything close to stock.

Was only thinking th350 because it takes me 4 hours to build one, cores are available, and they are a bit lighter than the Th400. Yeah a 400 would hold up ALOT better and it isnt that much more weight. Cant run a clutch since my knees are screwed up, otherwise that would be a natural.

If I can pull off the chassis and body work, some of the engines here would put it pretty well in the 9s, while looking like it runs 14s on a good day. Hence no race gas, smell gives it away. Sure it will take alot of time and fabrication, and some money, but time is one of the things I have plenty of. Provided I dont keel over anytime soon.

Have an Eagle long rod, Ross piston, combo on a 455 block in the machine shop right now. That will work untill an aluminum rod version can be built. Had the parts layin around, so we put them together.

Other than HO heads, for a D port a set of 7K3s (if using iron manifolds), 96, 5C, 6X, and the small chamber 4X max ported. Stainless valves, titainium retainers/etc. and a valve cover that has been sectioned and grafted to another one for a half inch more clearance to run full roller rockers. Could disguise headers a little with heat riser shields and like, but still visible under the front end. I have those heads sittin around, so they would be a logical choice. Would have to buy another set of HO heads. Right now the engine is just a shortblock, Havent decided on heads or cam as yet.

Could also go in a 71 Formula but the subframe connectors might give it away. the fiberglass door would be tougher to do with the length of the window glass too. Was thinking of building a 71 or 72 455HO Formula clone with it, and going F.A.S.T racing downstate.. Options and time.. Have plenty.

Any more engine ideas?

[65gto69]

Here is my new combo, it does have E-heads but had them painted pontiac blue to match the block, but have seen guys shave the "Edelbrock" off and put "6X" on the center port. Than they look pretty much like round port heads. Also I kept the points distributor but replaced the points with an Accel points replace kit, which changes it over to electronic. Put black MSD plug wires on it, and a torker II intake. Everything else is done on the inside, custom grond lunati solid cam 278/282 dur @ 0.050, eagle 4.25 crank, eagle 6.8 H rods, 60 over 400, brc pistons. Looks pretty stock to me.

Mark

go here for pics:

http://forums.maxperformanceinc.com/...d.php?t=495877

[Elarson]

Avoid the aluminum rods if you'll be putting a bunch of miles on it. Aluminum fatigues and is life limited. Good steel rods are not much more weight and will last practically forever. Aluminum rods are a better choice for drag racing with power adders, where they "cushion" the violence a bit and they can be removed after a set number of runs.

[screamingchief]

Well,I'll post a couple pics of my '72 firebird,now mind you this was "mocked up" just for these pics,it's "in process" right now,and this is'nt a final build yet,the final build will have an OE F-body dual snorkle and the pre-heat tube,now granted there are a few "compromises" on mine,but the overall look is pretty "sleepy" IMHO.
(shorty headers will be visible,but hey,,,we know those are no better than the RA manifolds right???)

Tell me what you think it would be capable of from it's appearance,then I'll tell you what is inside,not that it's anything special...

The bird will be wearing a '76 steel formula hood too,paint even matches the current paint by some weird quirk of fate,even though it was never on this car before.

Will be wearing poverty caps.

[issach428]

Screamin=Mid to high 12's if all motor. maybe mid 11's on spray?

[screamingchief]

Screamin=Mid to high 12's if all motor. maybe mid 11's on spray?

I'd say that's probably accurate,you have an astute eye,knowing what I do about ya from your posts here issach428,I'd say your not the kinda fella I'd expect to fool though,as you seem pretty hip to many of the tricks of the sleeper/street race trade.

Like I said,nothing special really,and for now likely no spray,at least not till I get back into the shortblock and go thru it,as the bottom end is essentially just a stock 455,cast pistons,fresh rings and bearings,so 5200 RPM's max likely.

Heads are ported #96's (250 ish cfm),stainless undercut flat faced valves,crower springs,1.65 rocker capable,blocked crossover,pretty standard "street/strip" iron heads,rockers are currently 1.5's.

Cam is a crower #60210 hydraulic for now.

Intake is obviously a torker II,edelbrock logo removed,painted engine color,will be port matched.

Carb is a reworked 3310 holley,with very subtle mods.

Ignition is stock single point housing,curved,and using the crane XR-1 igniton,painted blaster II coil,MSD black super conductor wires.

The exhaust will be the hedman shorties dumping into 3" 90 degree mandrel bends,then into flowmaster 3" to 2.5" "ball flange" collectors,then going into the flowmaster transverse 2.5" MB system,if anything gives this deal away it'll likely be this exhaust system,from all accounts I've heard this system is pretty loud.

Trans is a TH 350 I built,HD internals,good VB reprograming,convertor is a trans specialties 2400-2600 unit (likely stall to the high side of that),rear end will be a 8.5 3.23 posi that'll have the perches braced and the tubes welded to the center section.

Suspension will be pretty standard stuff,but will be adding SSM lift bars,decent adjustable shocks,and subframe connectors,with good body bushings,as I'm not too concern with it being a total sleeper,just want it to be generally under-estimated by the majority of folks who dont look at it too closely.

Considering I've been working with a virtually non-existant budget,I'd say it's coming along about as well as could be expected.

When I get a chance and some extra $$$$ I plan to redo the shortblock,good rods/pistons,and likely a better cam,probably a solid FT or maybe if I got the extra bucks a decent hydraulic roller,then I'll likely add a "system" for more,the beauty of the TII intake is it would be the easiest intake I can think of to add a plenum spray-bar into,looks like it was made for that to me.

Now lets see,,,use the top shot in the air cleaner housing for the first stage,the plenum spray-bar for the second stage,,,hmmmmm!?!?

But from just a glance,it looks just as "sleepy" as the 350 that came out of it,just a little cleaner and such at the moment.

But ya'll get the idea.

Needs a paint job though...

Bret.

[SLICK1]

Originally Posted by Brian Baker

Either a stroker 400 (4.25" crank with a 4.151" bore) or a 440" based on a 428 with aluminum rods and forged pistons.

Race ported d-ports yielding 10:1 CR (take your pick)...run 92 octane gas.

Edelbrock Torker-II intake (nobody will pay much attention to it with a Q-Jet sitting on it).

Worked over Q-Jet.

2.5" aftermarket ram-air exhaust manifolds that have been extrude honed.

Solid roller cam in the 270-280 @ .050" range, 110-lda.

Ditch the th350 and install a th400, with a tight 10" nitrous convertor. 3.73 rear gears.

Hide the nitrous plumbing into the manifold. With a 200-HP shot of nitrous, and some chassis tuning, a 3500 lb. car should see 9.90's in the 1/4 mile (or better).

Hide the fuel regulator and maybe run the plumbing through a "dummy" stock fuel pump (no guts, just there to look factory).

I LIKE THIS COMBO WITH THE 4.50 STROKE CRANK AND DITCHING THE TORKER II FOR AN EARLY FACTORY CAST IRON MANIFOLD HEAVILY PORTED & EXTRUDE HONED AND MODIFIED AS JIM HAND DESCRIBES WITH THE NITROUS PLUMBED UNDER IT FOR THE FULL SLEEPER EFFECT.