I am sure you guys can make this way less trial and error. I am getting a 455 that came out of a 71 riv originaly, and has been rebuilt 30, 000 miles ago and is presently in a 74 Chevy 1ton pick up that was used for towing (runs like a top) and is a total rust bucket. The motor is presently mated to a BOP th400 tranny. I am buying the whole truck for $1000 dollars, and will junk/sell the truck. The guys I am buying it from are pretty good friends, and I remember when they put the motor in the truck, so I know what I am getting. I want to put this motor into my 1965 Buick skylark, which now has a tired 300 4barrel ,and is a auto 2 speed,1 wheel wonder. What will I need to swap blocks besides new/diff motor mounts?Fan shroud ect........ Should I use the original transmission in the car, or the tranny out of the truck. If the truck trans. what changes would I need to make (cross member or driveshaft). If the cars original, what changes, tourque converter? Cross member? I would also like to install posi or Limitted-slip into the original pumpkin (10 bolt). Who/what would you suggest?
To do the swap you'll need to either get 455 frame pads and make them work, or buy the adapter pads from TA, I'd buy the adapters, they bolt right up and use the stock motor mounts. Now the transmission, I'm almost positive that the st300 will not bolt to the 455, and I wouldn't trust it with all the torque of a 455 even if it did bolt up. Use the th400, take the stock trans. crossmember, slide it back, bolt it to the trans. then redrill the holes in the frame to mount it down, if the car has a boxed frame, like my '65 convert., you'll have to make a mount that bolts off the stock location, and will pick up the new farther aft location. You will have to mess with the drive shaft, either way, short shaft or long shaft th400. I used the 300ci fan shroud, slightly modified on the bottom, if you want to run headers, TA has what you need, as long as it is NOT a stage 2 headed motor. The rear end, I don't know what would go into that housing. As I mentioned, I have a '65 Convertible that I race that had a 455 & th400. car ran 10.40s, soon to have the new Stg 2 motor. Good luck, Gary Giessen
One other thing to consider is how fast do you want to go??? A 455 with an after market intake about an 800 cfm carb, headers, th400 with like a 2800-3200 stall, and 3.73, maybe 4.10s, and you will run very well, around the 13.0 + second range. Gary G.
Thanx, I was just thinking about the project today and rememberd that the tranny in the truck has a transfer case bolted to the back of it. I think I could probably trade/swap this one for another. Can you/anyone tell me for sure that the tranny (st300) will not bolt to the 455. Didn't they use the st300 with the 401? I guess I asumed that the tranny would work for both big or small block, and the bolt pattern was the same no matter the year. If I have to go with the th400 or a 350 I will,but was just looking at other simpler options. I don't intend to drag race this car, but just want to put on a smoke show now and again for now :grin: The motor had a basicaly stock rebuild done to it, stock intake, carb, but does have a larger cam. I know that this motor will have gobs more tourque than the old 300, but that 2spd tranny kind of grew on me after I got used to it. Maby that was just wishful thinking that I could get another tourque converter and be done? How about the radiator? Will the stock one be enough to cool the BB? Front springs and swaybar? Airconditioning? The truck has Air, car does not, could you use that pump/compressor unit hooked/plumbed to a floor mount Vintage air unit? What about the Oilpan Is there a special on needed for the 455 to fit?
Pontiac used the ST300 behind the 389 tripower, so it should handle the 455 if you dont hammer it too much. If it does break then go build a TH400 and put it in. Although, I went from the ST300 to a TH350 and that lower first gear sure made getting off the starting line a lot nicer. Another thing to consider, since that truck was a 4X4 the TH400 tailshaft is completely different, and to swap it over to a 2 wheel drive config you've have to swap out the mainshaft in the tranny, thats a lot of work when you can pick up good th400's everywhere.
Elongate the holes in your frame when installing the frame brakets. This will save you hours of fighting. I wish someone would have told me to do that on the first try. Tom
65 Skylark-455 swap I think if your donar car for the 455 is a Riv it has a center sump oil pan, you need a rear sump. Not sure if all 455 Rivs had a center sump so somebody correct me if I'm wrong. I would look for a bigger rad also,maybe a 4 row from a air car.
:TU: 4x4 SKYLARK!!! That would rock!:eek2: I'm gonna have to do that some day. :Brow: smilies are dumb o No: :boring: uzzled: :error: ou: :spank: :sleep: :shock: lol
The BOP tranny should work fine. Most likely, you will need to just add the matching tail housing back onto the rear of the case. Maybe the guys you bought the truck from still have the original laying around? The ST300 2-spd was upgraded when installed behind higher hp engines, so even though it bolts right up, your original one won't be quite as durable. You can start off using the ST300 and keep your stock driveshaft and crossmember in place and be up and running sooner Then swap out the tranny later.
