'73 SD restoration
 

Greetings Gents,I have a white 1973 SD-455 Trans Am which was my treat to myself when I graduated college that year. Went from a starving student to making a few bucks. Actually bought it in '74 from a starving dental school student after hunting relentlessly for a '73. I didn't like the body style changes made and would have "paid extra" to get a '73.

Anyway....I'm planning out how to restore it (engine has 38,000 miles)and I want more compression but don't want to be cutting any metal. It is worth more unshaven and while I plan to change the cam, rockers, lifters etc I'm keeping all of the old components for whoever owns it next. So,I'd like the opinion of the gang. I want to raise the compression ratio as much as I can without shaving and without changing from a flat top piston. I have a set of TRW's which have compression bumps on but as many publications suggest, they mess up the flame front travel and are not a good change.

Long, long ago and in a land far, far away I had a '65 Chevrolet 327 which I was able to get the compression ratio a few points higher without shaving by using shim-type head gaskets. It took some custom making of intake manifold gaskets to get the geometry perfect but it worked great. What do you think about this approach for my SD?

Re: '73 SD restoration
 

Welcome aboard SlowPoke. Congrats on keeping her for 40 yrs. Pls post some as is pix and a few from back in the day! Thanks!

Re: '73 SD restoration
 

Welcome aboard!
Your Super Duty brother NJSteve is a member here and I expect will find you shortly.
[img]<<GRAEMLIN_URL>>/beers.gif[/img]
~ Pete

Re: '73 SD restoration
 

You've had this car from almost new (bravo to you) and you plan on changing all the valve train so why are you worried about the &quot;value&quot; of the heads? You've had it this long...A little bit of milling does the SD-455 a lot of good - especially when combined with a set of JE aluminum pistons ( don't have the part # handy but I will look it up - SRP also makes a good SD piston #149721), and nobody but you has to be the wiser. Here is an old school article on an SD-455 '73 T/A and the work that went into getting it to go faster using stock parts. It is old tech but still some valuable information.

A gentleman by the name of Steve Shappaugh has forgotten more than I know about getting Super Dutys to perform and he would be worth talking to - look him up online. It's a great engine and with just a point of compression, a good ignition and traction aids, it is a &quot;real street sweeper&quot;.

http://i962.photobucket.com/albums/a...sed849df1.jpeg

http://i962.photobucket.com/albums/a...s5b33ae00.jpeg

http://i962.photobucket.com/albums/a...s583c59bc.jpeg

http://i962.photobucket.com/albums/a...sb027b321.jpeg

http://i962.photobucket.com/albums/a...s794e5992.jpeg

Re: '73 SD restoration
 

mockingbird812, that ’69 Chevelle is the car I lusted after through high school. I lived in NJ until college and our street was on the edge of town, about 2 miles long. The guys 3 houses down had saved their money and bought an SS396/375 and I remember hot summer nights (no air conditioning in our house) with the windows open when they’d burn it out down our street after a bad date. Pure music.

Pete, thanks for the welcome. I’ll have to dig up some photos. No pics of her current condition until after some paint though. It was garage-kept until 2000 when we moved to Maine then it spent 3 years exposed to snow and weather until the garage was finished there. Building houses in Maine is not like any other state we’ve lived in. We live in arid Salt Lake City now and the dry weather is a good preservative for the metal.

Tracker, you’re echoing some of the mental debate I’ve had for the last 40 years….shaving or not. But my wife will likely live longer than I do and I want to leave her with as much money as possible. Then again, we’ve hauled this car all over the USA each time we move and I may decide to give it up myself after satisfying my curiosity of just how well it would do with some minor changes.

So far, my polling of collectors suggests milling the heads would lower the value. Now if when I take it apart, I find that the heads have warped then milling them would be the right thing to do and would increase its value over leaving it alone. Composite head gaskets are awfully thick so it seems a good way to do this but I don’t see many people writing about it which is why I’m asking for opinions. BTW, thanks for all the good info.

Does anyone know a current source for headers?

Re: '73 SD restoration
 

mill the heads, your wife will be fine. Hedmann makes great headers for Pontiacs - is this a 4-speed or an auto.?

Re: '73 SD restoration
 

SlowPoke, why not put the stock engine and tranny in storage and build a similar 455 that you can do whatever you want with it and not risk the $$$ loss of altering the original engine?

Just a thought, especially since the 70's T/A's are climbing in value rapidly these days.

Would love to see some pics.

Re: '73 SD restoration
 

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: markinnaples</div><div class="ubbcode-body">SlowPoke, why not put the stock engine and tranny in storage and build a similar 455 that you can do whatever you want with it and not risk the $$$ loss of altering the original engine?

Just a thought, especially since the 70's T/A's are climbing in value rapidly these days.

Would love to see some pics. </div></div>
Sadly I wish a kid I know took seriously the 72 H/O 4spd T/A that he inherited after his father passed. Wounded the engine within a few months, then left it sit outside for months (I barely remember it even seeing bad weather when his dad owned it) and I just heard that stacks of tires have fallen over onto it.

Re: '73 SD restoration
 

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.

Re: '73 SD restoration
 

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

Re: '73 SD restoration
 

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: PLATINUM6BBL</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: markinnaples</div><div class="ubbcode-body">SlowPoke, why not put the stock engine and tranny in storage and build a similar 455 that you can do whatever you want with it and not risk the $$$ loss of altering the original engine?

Just a thought, especially since the 70's T/A's are climbing in value rapidly these days.

Would love to see some pics. </div></div>
Sadly I wish a kid I know took seriously the 72 H/O 4spd T/A that he inherited after his father passed. Wounded the engine within a few months, then left it sit outside for months (I barely remember it even seeing bad weather when his dad owned it) and I just heard that stacks of tires have fallen over onto it. </div></div>
Saw the car over the weekend and happy to report the tire falling claim is false. I did snap some pics but have no way to up load them here.

Re: '73 SD restoration
 

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

Ryan

Re: '73 SD restoration
 

[img]<<GRAEMLIN_URL>>/3gears.gif[/img] https://www.yenko.net/ubbthreads/pics...205-455_ho.jpg
https://www.yenko.net/ubbthreads/pics...6-455_ho_2.jpg

Re: '73 SD restoration
 

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

Re: '73 SD restoration
 

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.

Re: '73 SD restoration
 

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

Re: '73 SD restoration
 

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.

Rubber and window trim (sqeegee molding?)
 

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

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:

Here is a link to some info on the door weatherstrip GM part numbers.

http://forums.maxperformanceinc.com/...t+part+numbers

I'm gonna X2 on this! I'd get another block and some Eddy heads and call it 455 SDlite! I had a 72 455HO I miss - traded it for a 69 with Butler heads on 455 that car is still alotta fun even though a good friend of min owns it now

I wouldn't listen to those magazines. They try to sound important by talking about the secrets that they hear from top level racers. Those racers are talking about pistons that are so high that they just about fill the entire chamber right to the top. Pistons with modest type domes will have the same or better flame travel than flat tops. Unless you have pistons that are designed for 12:1 or more I wouldn't worry about flame travel.