I finally cleaned out the shop side of the garage so I was thinking of working on the convert this winter. This car will be a very low dollar build, ie, as little money as possible to get it back on the road! The plans are for this GS to be our highway cruiser seeing very little, if no track time. It came to me with no engine, the numbers matching T400 installed which was supposedly completely rebuilt, and the numbers matching posi rear which had all the cover bolts loose, along with all the control arm bolts loose. The car had been sitting for over 10 years, I have no idea when there was last fluid in either the trans or rearend, so I'm a little leary of their condition. Here's what I was thinking of doing this winter. I just pulled a 8.5 non-posi 2.56 rear and a T350 from a '72 Skylark that was driven up from Texas within the last two years. I also have a '73 455 that was running a couple years ago and has been sitting inside in dry storage. Drop the whole package in and get the car running! I would like to keep the posi, how tough is it to find a posi carrier for the 2 series 8.5 gears? Will I have any problems getting the T350 linkage and kickdowns working with the floor console shifter? I have both trans crossmembers, does it matter which one I use? Can I use a '68 400 intake on the '73 block to keep the original look? I'll also be putting '68-'69 valve covers on it to keep the original look. Once you can drive cars you get a lot more excited about working on them!!
I believe the GS cross member has 2 "humps" for the dual exhaust while the "Sky wont. The Drive shaft will be be too short (Th350 smaller than th400). Not sure, but I think the 67-69 intake manifold bolt wholes are sized different than the 455's - maybe enlarge the wholes ??? You're gonna LOVE a DropTop '69 455" :TU: :beer :TU:
2 series 8.5 posi will be pretty easy to come by. Most late 70s Trans Ams came with a 2.41 posi. Bolts right in. If you have the driveshaft that goes with the tranny and rear you are set there. All in all sounds like a plan... You can only use the 68 intake with pre-AIR heads, unless you plug the 8 AIR passage holes on the intake face of the heads. 70-up heads have 7/16th intake bolt holes, but I think that 7/16 bolts will go through the holes in the 68 intake, which were intended for 3/8th bolts. If not, you can open up the holes as mentioned. Should be no problem with trans linkage. If your TH350 trans does not have the shifter cable bracket on the pan bolts I believe Mike G (racebuicks) repros them. For trans kickdown you will need a kickdown cable. (TH350-cable kickdown, TH400-electric kickdown)
