Hello, I have a 1964 Skylark convertible, 300 V8, original 4-speed car. Everything works fine but a 5-speed sure would be nice (especially since this is my wife's car). I have a T5 from a 1984 Firebird. By comparison on the floor it looks like it would practically bolt in. However, the shifter is in a different location. I don't want to cut up the floor as the only modifications I'm doing to this car are bolt on mods. Has anyone done this conversion? If so, can you tell me what I'd have to do to the floor? Many thanks, Joe
Hi, I have seen it done before, there was a 64 or 65 on ebay a few years ago (think it was on the east coast) running a SBB with a T5 in it not sure how much work it was to modify things to get it to work but the conversion has been done in the past I think Keisler has a trans that might work as it was advertised to locate everything in the same place as the 4 speed not sure how true that is though http://www.keislerauto.com/Keisler_Auto/Keisler_Engineering.html Good luck with the project, Regards,
Thanks, Jim. The Keisler tranny looks very nice but probably out of my price range. This winter I'll "simply" pull the tranny and see how much work will be involved. I'll report then.
Measure the distance from the front of the trans mounting surface to the shifter.... compare between the stock T-10 and the T5. Stock T-10 shifter mounts to the side of the tailhousing, and I believe the T5 shifter is centered on the tail? Floor will most likely need some cutting to fit the T5. Maybe you can use a different T5 tailhousing with a different shifter location that'll fit your '64 better.
Thank you, Walt. There are numerous tail shaft combos for the T5 (S10, Camaro, even Chevette) but they all just locate the shifter to different positions along the same top line. This will most likely require making a hole. The Keisler transmission cleverly put the shifter in the same place as the stock 4-speed. However, it's over $3500. Any thoughts from anyone on putting another hole in the floor of my original 4-speed Buick? Will I kill the value?
It might not be worth cutting up over a T-5 as there's a good reason why they never went behind a 350 in the third-gen Firebird/Camaro line-up and that's lack of strength. They are weak and prone to frequent failures when placed behind anything with even a moderate amount of torque. A 305 TPI (205 HP) is the biggest and meanest V8 that GM put these things behind from factory and about that time (86+) they were the newer slightly tougher "World Class" units and they weren't much better. If it was run in front of a 2.56 or 2.73 set of gears and never abused at all I could see it holding up for a while but depending on how it was treated before it might not. Not saying don't do it, it's just in my experience they have not been very sturdy. The mileage is certainly better and they are a nice smooth unit, but behind even a 300 SBB I don't think it would stand up to a lot of use.
I am aware that this transmission is not the strongest one available and that the later world class units are better but not best. The particular transmission I have came from an American Sedan track car. The first 3500 miles were track only. The next 125,000 miles were street but not that aggressive. It's been rebuilt with new bearings, synchros, and seals. The 300 Buick shouldn't be too much of a challenge especially since it's my wife's car and she is not necessarily an aggressive driver. These transmissions are smooth and can increase fuel mileage significantly if you do highway driving. Yes, they're not perfect but they are a very good compromise. For a total of $600 ($200 for the transmission, $400 for the professional rebuild) these trannies are a good deal. But I agree, best not to race them or put an real power to them.
There are over 100 variations of the T-5 transmission. In the 80 they made V-6 and V-8 versions for GM, you can tell the V-6 versions because they have a smaller input shaft. The ones from a Firebird would put the shifter right at the front edge of the seat and I'm pretty sure the cross member would go back and drive shaft may need to be shortened. The V-6 versions are all over the place for under $200, the V8 versions are much harder to find. Tremec makes a transmission with the shifter in the correct position for $2,300 that will handle plenty of power. Another option (as mentioned above) is to change to a 2.73 or 2.56 rear but your first gear will be real steep, and if you live around hills, you may have problems pulling-out from a stop with a 2.56 or 2.52 (transmission) first gear. To do that you would be better off finding a Saginaw four speed with a 3.11 first gear. That would put your first ger back almost where is was. you can pick up a 3.11 Saginaw for around $200 but watch out because these transmissions come with many different ratios all the way up to 3.54 first gears which you don't want. To get the full advantage of the new gearing you need to modify your carb so the power valve opens at lower vacuum. If you bog your engine it will lower it's vacuum characteristic which may cause the power valve to open per-maturly, so, you would be going down the interstate with the power valve open or partially open dumping fuel in that you engine doesn't need. Your power valve probably opens at 10 inches of mercury and it needs to be around 7 inches. You may go from 20 MPG to 22 or 23 MPG by changing the gears but you may go to 25 if you also did the carb also.
Shifter location on a '65 GS is about 17-18" from the trans front mounting surface. IIRC, a Skylark had a different floor hump than the GS, and a different shifter. Unsure if the hole location is different, but thought I'd give you a rough idea of the location.
Good tip with the power valve deal. Once I figure what I'm doing I'll measure vacuum at highway steady state. I've been out of old cars for too long. I'm used to highway cruising at 1600-1800 rpm. Seeing the tach at 2300-2500 rpm just seems unusual now. I keep reaching for the shifter to upshift. I think the rear is low 3's or high 2's. The car has plenty of power in all modes. We went from a high 2's to a 3.73 in my father-in-law's '69 Camaro and put in a 4-speed OD auto tranny. Incredible improvement in acceleration and cruise mileage. My plan was to put a 3.55 or 3.73 rear in the Buick when I go to a 5-speed. ---------- Post added at 05:12 PM ---------- Previous post was at 05:07 PM ---------- The T-5 shifter from the Firebird has the shifter 21" from the front surface. The S10 was probably at 15/16". Since the car has buckets I could put the shifter anywhere and put a kink in the shifter. However, the real need would be to put the shifter on the side. I haven't seen any hardware for that conversion, just new trannys. That's just too much change ($$) for me right now. Anyone have a winning lottery ticket they want to give me?
It would go nice with a 3.55, you don't want to bog the engine too much. Are you running a two or four barrel.? If you have an AFB it would be easy to change the metering rods and springs and the carb guys may have recommendations. I know Holley sells a power valve that doesn't open until 7 inches for use with over drive. I'm not sure how to modify a two barrel Rochester.
3.55 would be nice but not available for all rears (I don't know what rear I'll put in, I'll remove the '64 stock one and leave it that way and replace with another). The carb is a 500 CFM Edelbrock AFB type. It works really well right out of the box but once the gears are done I'll play with it. As far as the 2bbl goes, the best modifcation I did to it was to remove it.
That's the perfect carb for that engine. There's a couple of carb rebuilders at a monthly swap meet I go to. I'll see if they have any spring recommendations.
