'73 SD restoration

[njsteve]

Welcome! Now go to the Pontiac portion of this website and start a thread on your car, there. [img]<<GRAEMLIN_URL>>/biggthumpup.gif[/img]

Here's a couple of my projects:

https://www.yenko.net/ubbthreads/ubbthrea...-tre#Post539528

https://www.yenko.net/ubbthreads/ubbt...eux#Post487291

and the monster thread of them all:

https://www.yenko.net/ubbthreads/ubbt...ta-new-project

I would not get high compression pistons. The low compression Pontiac round port engines do not respond like a other engines (Chevies in particular) where raising the compression makes more power. 455HOs and SD455s don't like them and don't respond well to them at all. You'll just make it slower and addicted to racing gas. If you peruse the second thread above, you will see that the 455HO I had, had those domed 10-1/2 to 1 forged pistons installed and preignited like a monster - to the point where it left visible wear on the rod bearings and the timing could not be retarded back far enough to stop the knocking. And it was actually faster after I rebuilt the engine and installed forged 8.4 to 1 pistons.

A proper blueprinting of the engine will get you where you want to be. Everyone who has thrown a set of headers on a round port car ends up complaining about the leaking gaskets/flanges and winds up going back to the manifolds which were some of <span style="text-decoration: underline">the</span> best flowing cast iron manifolds ever produced. The best bang for the buck is getting a true dual exhaust setup with an x-pipe and without the crossover muffler. Also, getting the carb tuned properly will amaze you. The jets and metering rods need to be richened up by at least 10% to offset the 10% ethanol in today's fuels. There is a good 20 horsepower in that carb just waiting to be unleashed with the proper settings.

[KenMaisano]

Its very easy to make a Pontiac fly if you build them correct. They have very small port area and a long stroke. So you build them around torque not RPMs. One of my daily drivers is this 70 T/A its 440 inches. I had to sleeve all Eight holes because someone let the block rust. So I under bored it, I didn't want to break into water or weaken the deck. Then I added some stroke. its 9.6 compression D Dish .040 piston to head clearance, The key on these motors are they Love Wide lobe centers.
Cam 230/238 114. at 38' timing it runs amazing on our California watered down 91 gas. Ported #12 Heads stock plenum worked cast iron intake, Cliffs QJet Carb, Ram Air products Exhaust manifolds with a Pypes transverse ex. system. With a 3.23 posi, stock converter T 400. This car gets a average of 17MPG and will blow the tires off. This car is super fun and now right flys.
https://www.facebook.com/video.php?v=561...e=2&amp;theater

Ken Maisano

[Ryan1969Chevelle]

Hi Lon, If you e-mail them to me I can post them.

Ryan

[PLATINUM6BBL]

[img]<<GRAEMLIN_URL>>/[/img]

[SlowPoke]

Tracker1....thanks; good to know my wife will be fine I'll remember to check with you before my next stock trade. It is an automatic (bummer...always wished it were a 4 speed).

markinnaples...I've thought of doing exactly as you suggest and one day when I'm made of money I might just do that. But there is also that bit of curiosity in me that wants to see how well the engine can be made to run with a few modifications which basically fit into the category of &quot;un-doing&quot; the crap that the insurance and emissions lobby forced on the engine. My idea of what a muscle car should do was formed when I was in high school ('65-69) and I was always disappointed with the SD's performance. Granted, I knew much less about engines back then but I'd been in small block Camaros that were faster than this 455 beast (<span style="font-weight: bold">it just aint right!</span>).

I even thought of buying some new aluminum heads from Butler, but then it wouldn't be an SD455 any more, plus again there is that money thing. Perhaps I should pray that the heads are warped some and I find they need shaving, but it is unlikely because it has never been unduly stressed. No one has commented on the shim-type gaskets?

KenMaisano....440 CID, interesting that you are just 7 inches over the displacement Greg Peterson chose for his SD modification which he wrote about in the High Performance Pontiac article. Did you have your own cam ground or is there a standard part number you are using?

Thanks NJSteve I look into how to perhaps &quot;move&quot; this thread to the Pontiac area.

JM

[NOTIME]

Talk to Dan Jensen. He built my HO motor with no cutting, used Diamond pistons to get compression up to about 9.2:1 with a roller cam and eagle rods and dynoed at 475 HP 554 ft lbs. on 87 pump gas.

I am getting ready to restore a 73 SD 4spd and hes doing the motor, owner wants about the same.

[tjs44]

I agree,talk to Dan or maybe Rick Johnson in Crete IL.Rick has helped Dan and Scott Tieman with some of their builds.Also dont be afraid of a small properly done dome.There are MANY hipo race engines running them.Tom

[RichSchmidt]

I would change the pistons,do a mild cut(.030&quot AND go to a shim gasket if the deck clearance if .020&quot; or more. I have heard that the SD cam is stout and runs strong if you retard it 4-6 degrees. A 3 angle valve job,back cut the valves,and you should have a stout piece. If you are buying good pistons with small rings,then spend the extra bucks for a gapless set,and have the block plate honed. I don't know what valves the SD comes with,but if the faces are recessed,you can go with nail head valves to bring up the compression.

[SlowPoke]

I’ve seen many places advertising rubber and trim for ’70 F bodies but would like the recommendation of the collective……

Most things are still in great shape but I’ll have to replace some window molding and the squeegee molding (not sure of the name of it, but it is between the outside of the door glass and the body).

I've hesitated to put this under a separate Pontiac restoration thread because I'd be embarrassed at going so slow. Not long after starting this thread, I started a project to rebuild the engine in my ’92 300ZX twin turbo, which is in such good shape I wouldn’t even call it a restoration. Once the engine was out, creeping elegance set in as I kept seeing small things which are easy to do with the engine out. I’ve done picky things I never intended to do. It needs to finish before I start making good progress on the SD.

Things went into suspended animation after having 3 major surgeries in 3 months. My body wasn’t actually ready for it but I wanted to take some of the interior plastics out before the furnace of summer set in but also with the sun’s radiant heat warming things up so the plastics wouldn’t be brittle.

Today was perfect so I took the seats out and recon’ed the situation. I replaced the headliner in ’83 and although it still looks good but I’m thinking it can’t be so I’ll be looking for vinyl which matches. I'd not remembered how heavy the seats are. I wonder if there is a lighter alternative?

Thanks all

[njsteve]

You definitely should move this thread over to the Pontiac section just for ease of finding it.

There are two different outer door rubber "squeegee" moldings as you call them. It depends on whether you have the stainless steel molding on the top of the door or not.

This molding, outlined in red: