1987 Grand Prix Project
- Thread starter 87PontiacGP
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Sounds like a great project. I dig the Buick motor idea, although the SBB/G-body combo isn't one I've heard much about. What frame mounts would you use? Too bad there are no headers available. I particularly like the fact that you're going sort of sleeper/original with the bench, stock wheels, etc. It's a pretty unique route these days, it's the way I went. Also dig the hood tach idea, I can't stand the dash tumor tachs, but having a tach can be useful. Good luck with it!
Intragration said:
Thanks much. I've always liked the Buick engines and found out from research that SBB's are usually underrated by most people. You can get decent power from a Buick 350, enough for my goals anyway as a daily driver with some spunk. I like the fact that the Buick 350 is the lightest of the GM 350 engines, stronger design, and makes a boat load of torque down low. I have toyed with the idea of a BBB 455, but that will be for my next classic car which will be a Buick since i have to say fair well to my '69 LeSabre.. 🙁 I like having something unique and, like you said, not many leave their car stock looking stock. Plus I had the engine laying around was good enough reason for me to dive into her. It does cost a little more to have a "gentleman's small block", but I'm alright with it. I did find headers, but they are pricey and I'm not sure of the fitment. TA makes some and so does Hooker (which I will be showing in an update for people's opinions). As for the engine mounts, I'll probably have to try and fabricate the ones from the LeSabre into the Grand Prix, unless there are mounts that will work that I'm not aware of. :? Then again that's why I made this thread, to learn as much as I can from those who know. Thanks again!
I'm not usually an advocate of double posting but, 
for updated ideas at the bottom of the first post. 
for updated ideas at the bottom of the first post.
I've got the Hooker BBO G-body headers, I'm very happy with them. It's a complicated fit, and they fit perfectly. I would recommend them highly on fit and finish, might want to just check with others who have done the Buick swap. The Chevy 2004R will be a problem. Since you've already got the TH400, you could always run that, even if it's just temporarily. If long term you'd like the benefits of the OD and also the ability to run a lower rear gear, you could look for a BOP 2004r. The 2004r and the 400 are the same length to the trans mount and tail (on the short 400) so you wouldn't have to worry about that aspect of interchange. My recommendation on the rear is to just leave it alone for now. It should hold up to the power, I'm currently running a 2.41 7.5, not ideal, but it's working for the time being. I am planning to go with an 8.5, so it didn't make sense to mod mine. If ultimately you decide to keep the 7.5, a posi and gear would be straightforward. Again, I think it will hold up to the power, especially if you're not looking to seriously race it, run slicks, etc. Here's how I modded my crossmember to clear the drivers side collector. Made sure it fit with the trans, outlined where the collector pointed, a little cutting and welding, done.
Overall, my recommendation and the way I did it, would be to find the shortest path to getting the swap done and getting the car running and driving again, without spending a lot of time and money on things that can or will be changed later, i.e. trans, rear. Since the 2004r and 400 basically interchange (check on yokes, I"m not positive about this) even if you wanted to do overdrive later, I'd say go with the 400 now to get it running. On the rear, you can always do a gear or axle swap later, and it doesn't cost you anything to get it running now with what you have. Then, once it's running, you can always tackle individual projects as you would with any car. Obviously, don't spend money to rebuild the TH400 if your goal is to go OD, but don't spend lots of time holding up the project just to source and build the 2004r if you think you can live with the perfectly functional 400 for the time being.
Overall, my recommendation and the way I did it, would be to find the shortest path to getting the swap done and getting the car running and driving again, without spending a lot of time and money on things that can or will be changed later, i.e. trans, rear. Since the 2004r and 400 basically interchange (check on yokes, I"m not positive about this) even if you wanted to do overdrive later, I'd say go with the 400 now to get it running. On the rear, you can always do a gear or axle swap later, and it doesn't cost you anything to get it running now with what you have. Then, once it's running, you can always tackle individual projects as you would with any car. Obviously, don't spend money to rebuild the TH400 if your goal is to go OD, but don't spend lots of time holding up the project just to source and build the 2004r if you think you can live with the perfectly functional 400 for the time being.
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Intragration said:
Ya, I'm really thinking about those headers, and I've heard from a few people that they should fit. I thought more about the transmission situation after posting the updates and decided to go that route. Bolt in the Th400 for now and get the TH2004r beefed up to handle the stress of the power I'll be making. One thing though, I was under the impression the TH2004r was mostly a B.O.P. transmission, but also universal for Chevy engines? So I shouldn't need an adapter as far as I am aware? But like you said I'm tackling this project in stages. Working on a little at a time, but yet still have it drivable. I also have to tear into the Buick 350 and check it all over since it has been sitting for a little while. Should be all good though. For now I'll be driving the Grand Prix in stock form till the mods. Once the Chevy 305 is out and the Buick 350 is ready to go in I'll be most likely upgrade the rear end, modifying the crossmember, and installing the TH400. Get as much done while I'm under the car as I can. Then, once I save enough for the transmission upgrades and have them installed, I will be taking the transmission out and swapping it for a TH400. Also I will keep the 7.5" and changing out the gears. I don't plan on launching it like a mad man, nor do I plan on really tracking the car. Maybe a few times but not a whole lot. It'll be just a fun daily driver, my next project will be my fun, classic track car. 8)
Thanks for the pic of the crossmembers. It looks similar to what I had in mind.
You could be right about the bellhousing patterns, you might have what you need already. Sounds like you've got a plan, good luck!
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