[wynter919]

First off im not a engine builder or even a intermediate at engine knowledge so sorry if what i say is a little vague or retarded im sorry , but i have a 1970 400 (290hp)(not ram air heads) engine im dropping into my 1980 TA.

Before it goes in i want to up it to about 375-400 bhp and i have a very vague idea of what i want to do to it as shown below.....

Eagle rotating assembly - 461CID, stroke 4.250 in, bore 4.155
oversize 0.035 in

COMP Cams Xtreme Energy Cam and Lifter Kits,Cam/Lifters/Valvetrain, Hydraulic Flat Tappet,Duration 274/286, Lift .488/.491,
(though i have no idea how to work out duration and lift,just need a cam that will work well between 1800-5,500rpm and works well with the engine kit)

Carburetor, Proform Street Series, 750 cfm, 4-Barrel, Dual Inlet (but not decided yet) (running 99 octane)

Holley Mechanical Fuel Pump (110gph 6-8.5 psi)

i will but upgrading rocker arms ,pushrods, oil pump and other bits to match

the heads and intake will stay the same , so basically im upping the engine to 461, putting a more aggressive cam setup and a fancy carb on as well as possibly increasing the CR

with this kind of setup (i know very vague but u get the idea) b able to put me in the 375-400 hp region???
If not why and how can i achive this figure without touching heads or intake???
thanks for any help

[455Grandville]

Keep in mind with those heads ( # 16s ?) you may not get by with pump gas(Your compression could be a little too high) If those heads are 1970 models - they might have been previously milled (and if so, how much ?) raising the compression even more.
Another consideration (again, dont know what heads you have) when raising the displacement you should up the breathing of the heads. What might have been OK for 400 cid now needs to feed 461 cid. If they are the small (1.96") intake valve heads; I wouldnt bother. Do they have pressed in studs or screw in studs ?
If they are 1970 heads, you'll need to convert them for unleaded fuel (hardened exhaust valves/seats)
You might want to find some 6X heads, but whatever floats your boat.

[wynter919]

the heads are 1970,290HP,16(small valve)1.96/1.66,10 c.r. 78cc (pressed studs)

is there no reasonable way to push my 1970 block with these heads up to 350-400hp? or am i def gonna have to look at new heads ???

[BruceWilkie]

With the increased displacement you will also gain compression. I would say that if you do indeed have 99 octane gas and a cam similar to say a RA4 grind you could make a lot of power. The 16 heads with their small valves will choke your power down to probably 350+. If you go to large valves and do some porting 450 is doable. A ported set of aluminum heads will net even greater power levels (potential 500 or more depending on cam intake exhaust etc.) and also provide greater tolerance to lower octane fuel.

[Will]

You could order dished pistons with your stroker kit to get a streetable 9-9.5:1 CR with your existing heads.

Then have the large valves installed in them and get them converted to screw-in studs. They'll still need some port work to flow as well as an original large valve set of heads, but with porting they can go up to around 240 cfm easily.

Depending on your goals and budget, it may be easier and/or cheaper to just buy a set of 6X or 5C heads, or some Edelbrocks or KREs and be done with it.

With good flowing heads, 400 horsepower from a 461 cid engine is easy as falling off a log. If you were to put some Edelbrock heads on your engine, keeping everything else as you outlined, you'd be closer to 475-500 horses.

The power is in the heads!

If your budget is limited, then forget the stroker kit and buy some good heads instead. A set of 72cc Edelbrocks, and a Crower 60916 cam in a 400 should easily make 400 horses.

[goquick]

You don't need that stroker kit for that hp range. Budget sounds a bit low to begin with so why not do the 400 as a 400? Saves money. Even the heads you have will be able to make the hp level you want. To make the heads work you have, I'd put in 2.08" intake valves and 1.71" exhaust valves after changing the heads to screw in studs. I would look at a hyd roller cam so you could have a better profile for better driving. But if you want a flat tappet type then a cam along the lines of the Comp Cams 286AH-12, with 236/244 @.050", .489"/.500" lift (1.5 rated ratio) 112 LSA,(makes it able to run pump gas, otherwise a 110 lsa). A TYPICAL dished piston in my opinion isn't the way to go here. Too much quench loss. I would get the Speed-pro pistons, rings, and a good aftermarket stock lenght rod. So close to cost of fixing and reworking stock rods anymore, it's not worth chancing the stockers. Try the new Melling Select oil pump. You will like the hot oil not losing pressure with it like can happen so easily with the others.
What intake do you currently have? I'd go either Torker II (because of hood clearence) or performer RPM. Get a 1 3/4" primary 4 tube headers not the lousy power robbing poj's 1 5/8".
Holley Street Advenger 870. The most tunible and easest to do so street carb holley has ever had. Tuned will deliever good drivability.
I made over 425hp with this same combo and the 70 small valve #16 heads with the installed larger valves I recommended..

[wynter919]

the intake is 496140 , 1975 Q jet.
ideally don't want to change the intake if possible.
how expensive is changing the valves and studs? is it just a matter of buying the parts and fitting them straight in, or do they require machine work?

thanks 4 the help

[Will]

Originally Posted by goquick

.... Try the new Melling Select oil pump....

??? What's the part number? Different than the M54?

[goquick]

Not sure on part number.

On that intake, it is the egr style. I'd Go for either an earlier pre egr intake or get an RPM perfomer. But if you want that one (1975), then I would get a 77 or 78 Q-Jet from a Pontiac 400 to use. You won't beat it for all round driving plus they are 800 cfm. And it looks stock. Using adaptors to mount the other type carbs on the Q-Jet intake is a bad joke.

My cost on the valves is under 175. Not sure what the price is on the studs right now. Haven't done any in a year or so. And then I used the new ARP studs I already had. Shouldn't be more than 600 unless you need guides.

[wynter919]

ok, thx thats cleared alot up,jst a few more Questions if i can...

1.is the Egr such a big problem? can it not jst be not used or sumthing (really know nothing about this area)and im a little confused about adaptor plates , are they really that bad and not worth it??. i thought the Holley's Street Avenger would fit right on my intake or so i was told!?

2.and to be honest i have no idea what press studs or screw in studs are or do. is it really needed to change from press to screw studs and if so is this along the lines of what i need...and will they fit right on or does it involve machine work????
http://store.summitracing.com/partde...3&autoview=sku

3.a performer rpm intake is not out of my price range, was jst curious about the above.
From the looks of it i want a very simialr setup to what u have and you say you got over 425hp??

[goquick]

The egr intake can be used, but I wouldn't use anything other than a Q-Jet on it. It's just you are giving up alot of power with it. For this type application, I know what worked best for me was the RPM intake. Since this is going in the T/A, then might even look at the air cleaner assembly from Larry (WFO) who is on the forums here just for the clearence under the stock hood and still look right.

Your current rocker arm studs are a press in style. Under higher lifts and spring pressure that goes with that, the stud can raise up out of position. Screw in rocker arm studs once in laced and torqued, stay put, there by not being a loose rocker arm issue later like a press in stud will be. The hole needs to be tapped for the threaded bottom on the new studs. On Pontiacs, the bottom is already a 7/16" dia., even the press in style. The studs you need are either a 1/2" bottom or you can get thew holes reamed/threaded for a heli-coil set up as some do for a 7/16" bottom also. The ones listed on your link is for a stronger factory replacement style ARP that has a 7/16" bottom.

[wynter919]

kool, thanks for the help, cleared up all of my question, now know what direction to head in.
Thanks alot

[455Grandville]

Originally Posted by goquick

Not sure on part number.

On that intake, it is the egr style. I'd Go for either an earlier pre egr intake or get an RPM perfomer. But if you want that one (1975), then I would get a 77 or 78 Q-Jet from a Pontiac 400 to use. You won't beat it for all round driving plus they are 800 cfm. And it looks stock. Using adaptors to mount the other type carbs on the Q-Jet intake is a bad joke.

My cost on the valves is under 175. Not sure what the price is on the studs right now. Haven't done any in a year or so. And then I used the new ARP studs I already had. Shouldn't be more than 600 unless you need guides.

Goquick , I thought around 75 or 76 the Q jet intakes were restricted with that squared off secondary passage - So, did the 77 - 78 intakes on T/A's lose this bs feature ?

[chiphead]

I'd find a different set of heads. There are 3 main problems with using small valve 16s on a 461.

1: Compression will be too high. It will require the use of race fuel at $6 a gallon, or a set of $800 dished pistons.

2: The valves are too small for a 461. Big $$$ for the conversion and porting.

3: The heads need converted for screw-in studs.

It will cost you as much to properly prepare these heads for use as it will to buy a built set of 5C or 6X-8s, or a set of 87CC edelbrocks.

As Will said, the power is in the heads and manifolding. Using low-performance heads on a big-cube bottom end is a mistake. You'd might as well run the 400 as-is.

Ditch that smogger intake into the closest scrap bin. Performer RPM and Q-jet all the way.

The XE274 cam is wrong choice unless you get the compression down below 9.5 with iron heads, or 10:1 with aluminum. The XE cams build cylinder pressure and will detonate on a large, high compression engine. A Crower is likely a better choice for a high compression 461.

And spend the coin on a good windage tray and oil pan. Use ARP head bolts. And have that Eagle crank checked 9 ways to sunday, some had machining problems.

Spend the money on proper block work. Zero decking, torque plate honing, magnafluxing, etc.

You realize this engine is gonna cost $4500, right? Pontiacs cost $10 per HP to build.

good luck, chip.

[goquick]

455Grandville; I was refering to using just the 77-78 Carb. As for intakes, unless someone knows something I don't, then i wouldn't use the egr style intakes at all.
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As for cost vs. performance, I think he is thinkng that he'll do the 400 as a 400. The small valve heads are fine and is not any more expensive nor will they perform any worst than him going and finding a set of big valve heads and having everything done to those. Tho only advantage to him going and buying the big valve heads is wiped out by the additional cost or purchase, and that is the rocker studs. But I am of the opinion that the small valve heads once converted to screwin studs with the larger bottom dia., is actuly a stronger stud and less prone to break if someone ever steps up to high pressure/high lift set up. As for porting, that's a wash if they are done to flow the same.

[Will]

Dyno testing has shown the EGR intakes, even the ones with the squared off secondaries don't lose much in a typical street engine to the earlier intakes. They're a lot heavier though, and if you're upping the RPM potential of the engine or running a big cube engine then something with a larger plenum would probably be better.