[The Boss]

Just like the title says, I'm looking for a Super Duty recipe.

Back when all the work was done on my 73 TA http://forums.maxperformanceinc.com/...d.php?t=743806 the original owner had HO Racing build a Super Duty motor out of over the counter parts for him. I've been in touch with Craig Hendrickson but he does not seem to remember the particulars of the build (It was almost 40 years ago).

Since that motor got pulled, I'm looking to put another one back in and am looking for a build recipe. Parts I have for the build are:

73 Dated 485428 casting 4 bolt main 455HO SR Block
#16 Super Duty Heads
72 Dated (early) 485640 Aluminum Intake Manifold
SR Dated Super Duty Carb (can't locate it at the moment to pull the number)
L Casting Super Duty Rods
Standard 455 cast crank

What I'm looking for are the particulars on how I should build this to have a strong street engine & occasional track run that will run on 93 octane pump gas. What compression ratio, stroke, rods, pistons, cam and what other considerations I should make for the build. There is an electric fuel pump on the car and I've already purchased a new fuel tank with one in it so we can take that into consideration as well.

Not looking to spend a fortune, I probably won't end up using the rods due to weight but can easily sell those. I have not purchased exhaust manifolds yet but plan to go with a stock transverse muffler setup so over-sized is likely out.

So - what would you suggest?

[Gary H]

I've got a 73' green SD car myself. Mine is much closer to stock than this but still runs great. I've build several of these engines over the years and here's my thought on your build. You didn't mention having a crank so I would get a forged 4.250 crank (versus the 4.210 stock stroke), use 6.8 Eagle rods, get Ross pistons to match with a moderate dome to get you to around 9.5 to 9.75 CR. Use a hydraulic roller camshaft and don't put too small a cam in it. I would go with something like the the old faithful cam (236 I 245E @.050) but ground on a 114 LSA if you are going to run the factory SD manifolds. When you buy the manifolds have them opened up to 2.5" Modify the intake plenum or send it off to SD performance to be worked. Put in around a 2800 stall convertor. Zero deck the block and hone it with a head plate. The car will flat out get with this combination!

[Skip Fix]

There was a post a few days ago about a sale on forged 4.21 cranks. I'd sure do a forged to protect the rest of the investment.

Those SD intakes are REALLY heavy. I had one a 73 a few years back. Depends how you want it to look-I'd opt for an original HO intake.

I have 2 replacement SD Qjets and they are great right out of the box.

SD rods are heavy also-why I sold the set I had.

[77 TRASHCAN]

I vote for Cliff's recommendation, whatever it turns out to be...

The RPM crank on special I saw was a 4" stroke crank...3.25 main

[johnta1]

I'd get a 'big' roller cam and use some good springs.
I looked for some Ultradyne etc cams, seems most aren't made anymore or not advertised.
Probably try SD Performance.

I ran a Comp Cam like what HO Racing ran in their SS TA.
Had something like .720" lift at 104º LSA.
Used CC 999 springs also.



That was with the flat top stock pistons.
That engine was wicked.

I also used 2" headers (JR Headers).

It would idle and run great, did run a 4000 RPM stall converter.

Personally, if cam doesn't have at least .600" lift I wouldn't mess with it.
The SD heads want to breathe!
(I also used the Torker I but the aluminum intake you have would probably work good. I did use a 3" spacer on my intake which helped a bunch)

[shaker455]

Originally Posted by The Boss

Just like the title says, I'm looking for a Super Duty recipe.

Back when all the work was done on my 73 TA http://forums.maxperformanceinc.com/...d.php?t=743806 the original owner had HO Racing build a Super Duty motor out of over the counter parts for him. I've been in touch with Craig Hendrickson but he does not seem to remember the particulars of the build (It was almost 40 years ago).

Since that motor got pulled, I'm looking to put another one back in and am looking for a build recipe. Parts I have for the build are:

73 Dated 485428 casting 4 bolt main 455HO SR Block
#16 Super Duty Heads
72 Dated (early) 485640 Aluminum Intake Manifold
SR Dated Super Duty Carb (can't locate it at the moment to pull the number)
L Casting Super Duty Rods
Standard 455 cast crank

What I'm looking for are the particulars on how I should build this to have a strong street engine & occasional track run that will run on 93 octane pump gas. What compression ratio, stroke, rods, pistons, cam and what other considerations I should make for the build. There is an electric fuel pump on the car and I've already purchased a new fuel tank with one in it so we can take that into consideration as well.

Not looking to spend a fortune, I probably won't end up using the rods due to weight but can easily sell those. I have not purchased exhaust manifolds yet but plan to go with a stock transverse muffler setup so over-sized is likely out.

So - what would you suggest?

I have the same parts too and I'm considering stroking it to reduce dome size as much as possible.

[Skip Fix]

Bullet can grind any of the UD cams. I think Lloyd Coulson had an UD in his first TA years ago in the late 80s with SD clone motor. It had a Torker II.

[PAUL K]

I think it would be sack religious to install non American made connecting rods in a SD build when you already have a useable set of SD rods. JMO
I would concentrate on the cylinder heads and camshaft. That will make the difference between jaw dropping performance or average power. I posted a build in the 70-73 tech section under the Super Duty Forum thread on my 74 SD that ran 12.7 weighing over 4300 lbs. using 3:08 gears.

[The Boss]

Is a forged crank necessary if I'm not planning on going beyond the normal 5-5200 rpm range? I already have a stock cast crank - won't something else go first? If changing the crank, should I stroke it? If so how much? Eagle has crank/rod/piston assembly's and I'm sure others do - would that be the route to go?

Will going to a roller camshaft require me to machine the block for the lifters? Is the gain in profile worth the expenditure?

Thanks guys, still learning.

[Gary H]

The factory crank will be fine for what your doing. But, if you were going to buy a crank then I would go with a forged 4.250 crank which is slightly longer than your 4.210 factory crank. The Eagle of other brand complete assemblies are a pretty good deal, but I would stick with your crank, get some H beam rods, and spend the extra money on a custom piston to get your compression up some, and a roller cam. You don't have machine the block for roller lifters. In my opinion, yes, the extra performance and reliability is worth the cost to go with a roller camshaft versus a flat tappet.

[johnta1]

X2 on what Gary said.

If you use the stroker crank, the block needs checked at the front for the counter weight hitting. But a 455 block usually doesn't need it.

Otherwise it's all drop in.

Super Duty Power to the Front!

[Cliff R]

We've done several 455 HO and Super Duty engines.

They have EXCELLENT potential in pretty much stock form, so no need to stray to far form the stock configuration.

We've done absolutely stone stock 455 SD's, and a few with some head porting and other improvements to raise the SCR some.

The only negative of the 455 SD's when it comes to making power (torque) is the relatively "low" static compression ratio, but that's not a big negative if you take a few steps during the rebuild to cure that issue.

My recipe for a nice 455 SD build is to ditch the heavy factory rods and pistons, and go with lighter "H" beams with Ross, KB, or Icon pistons and two valve reliefs.

Zero deck the block, and cut the heads about .030" or so. Shoot for .035" quench, plus or minus .005". With "max effort" builds, the tighter the quench the better. The heads can be cut further for more compression, but I'm not a big advocate of that deal as they are nearly impossible to replace, and you start running into issues with intake fit, valley pan sealing (cutting the intake face accordingly) etc. A slight dome on the piston is another option, but not one I'm a big fan of here. Had a few in here to tune that HATED pump fuel with the small dome in them, so we pretty much stay away from that deal for these builds.

No need for any head porting, good valve, seat and a little bowl clean up is plenty, but it is an option if you don't mind spending the extra funds.

Stock intake and exhaust are fine, as is the stock SD Q-jet.

Since we've improved quench and raised the SCR closer to 8.8 to 9 to 1 we can now install a well chose HR camshaft, or pretty big flat tappet cam with Rhoads lifters and high ratio rockers on it. The end result is pretty much the same, but with the HR cam we can get it all done with less seat timing, and a bit more vacuum at idle speed and better street manners.

Either one will get you right at 1hp/cid and over 500ft lbs torque across most of the loaded rpm range. The ones we've done and dyno's have ranged in the 440hp to 500hp range, and most made 530-560ft lbs peak torque.

They will EASILY manage pump fuel at that power level, and can be tuned for 87-89 octane without much trouble, no need for 92-93 octane in most cases.

Basically the SD engines were one of Pontiac's best efforts thru the smog years. No real need to re-invent the wheel with them, just go in and help them in a few areas and good to go.......Cliff

[PAUL K]

To accomplish your goals, a forged crank and rods aren't going to buy you anything, the power will come from the heads, cam and pistons.
Considering the look of the car (which IMO is really cool) , I would build the engine with a HFT and use Rhoades lifters so the engine sounded like it had mechanical lifters. I would also consider running headers and have them coated black so they look period correct. Having grown up in the Era that car looks like it was built , I can't imagine watching the guy popping the hood and not seeing headers (unfortunately it probably would have had a Torker manifold also)
If you used your existing crank and rods, and went with a HFT cam you will save enough money to be able to have a competent shop set the heads and intake manifold up to achieve your goals.
However if it's in the budget go for a 4.5" crank, a hydraulic roller cam, port the heads and you should have a low eleven second pump gas SCREAMER!

[Larry Navarro]

My experience with a service replacement SD455.........12.70's @ 108 mph and street friendly on pump gas.
The HO-racing HC-63 cam (242/255 on a 115 LSA), STOCK 8.4:1 pistons, #16 SD heads with slight bowl clean-up, SD carb but opted later for Brad Urban tuned 750q-jet, heavy SD455 intake, H-O racing Tri-Y headers, full 2.5 exhaust w/flows.
Now this was a 4 speed t/a car so I don't know how an auto would fair with the HC-63 cam. However, it wasn't a problem with power brakes.

Fooled many BBC guys when I opened the hood and they saw all that stock stuff.
Even had a couple of guys were looking for a nitrous setup....LOL.

[The Boss]

All good stuff guys, thanks.

Probably going to bring the block & crank to the shop next week to get everything checked and figure out what I need to pick up for rods & pistons. Cliff, I'll probably be shipping the carb out to you as soon as I find it, so that I can get it in the cue. And will probably be sending the intake as well for a little throat cleaning.

Anybody looking for a nice set of SD rods?

[Cliff R]

The SD rods are still quite popular, so selling them can offset the cost of the build some.

WAY better to go to a modern lighter rod, that's already set up for full floating pins. Just a lot better deal all the way around than using rods with zillions of cycles on them already and getting them rebuilt with new bolts, etc.

Also look closely at Larry's example of a relatively "low" compression 455 SD build and it's potential. They don't even grumble with those big HO Racing cams in them, yet we continue to see folks putting little tiny cams in them, then making no more power than a similar 455 build with 6X heads on it. The 455 SD is a factory "race horse", cam it up and let it run!.....IMHO.......Cliff

[Larry Navarro]

man that car was a blast to drive.
Later I added moser axles, c-clip eliminators and 3:90 gear. Put a pair of sticky McCreary tires on the rear and that car would yank your head off.
Wish I still had it.

[Larry Navarro]

Let me add a funny story to this car. I bought it in the rain, took it for a test drive and it was sluggish, no power but bought it regardless...........it was a SD455 !!!
I had intensions of tearing the engine down anyway so it was no big deal.....figured I'd make it run like it should.
Make a long story short, for whatever the reason, someone had installed a 421 crankshaft. The pistons were "in the hole" about 1/8" of an inch !!
yeah, weird shizz.

[Bruce Meyer]

Originally Posted by Cliff R

The SD rods are still quite popular, so selling them can offset the cost of the build some.

WAY better to go to a modern lighter rod, that's already set up for full floating pins. Just a lot better deal all the way around than using rods with zillions of cycles on them already and getting them rebuilt with new bolts, etc.

Also look closely at Larry's example of a relatively "low" compression 455 SD build and it's potential. They don't even grumble with those big HO Racing cams in them, yet we continue to see folks putting little tiny cams in them, then making no more power than a similar 455 build with 6X heads on it. The 455 SD is a factory "race horse", cam it up and let it run!.....IMHO.......Cliff

I agree 100%. In the past I ran a set of stock 71 HO heads on a 455 w/flattops. I had an Ultradyne 239/247 112 LSA. It only had 8:1 and ran great. Pushed a 3965 pound car to 12.70. On 87 octane.

[The Boss]

12's would be great, not looking for anything more than that.

I nice lump or shake at the stop light would be nice - I always like that feeling - and a good burble out of the exhaust is cool too.