hey guys, just picked up a 68 350 engine backed by a turbo 400 trans, I know the motor will bolt right in but what about the trans? will be putting it into a 76 skylark. thanks, keith
What trans do you have now? What engine do you have? The 400 trans will "fit" but you will need to make driveshaft mods, move crossmember etc forsure.
As stated, you will need to move the crossmember, or, if it's one of those for single exhaust only, get a new one. The driveshaft will need to be shortened. It would be a good time to get new u-joints and it will get balance. Don't let amateurs do this. Find a reputable shop that specializes in drivelines to do this. Ask around. Get references. The TH400 swap has been done many times so it's very doable.
It's a 76 skylark with the v6 and 200 trans, I picked up a 68 350 4bl 280hp engine backed by a turbo 400 thanks, keith
You will want to find a th400 driveshaft to steal the yoke from as the 200 one have a different spline count on the trans end... The engine mounts will need to be re-used off of the V6 onto the 350 but no other mount issues there... You should be able to buy new mounts as the old ones are usually trashed... Just be sure to get the V6 mounts. What I would do personally is pull the old engine and trans together because it is easier... Loosen the crossmember bolts. Then mount the new engine and trans together, move the cross-member (add new th400 mount), and then have a driveshaft built to fit.
If that 400 is a short tail, it should fit the space. The rear mount needs to move back 6 3/8". As mentioned, since the 400 has a much larger dia output shaft, you will need a different yoke. But if you use the shortest yoke, you will probably be able to use the SAME drive shaft. I have replaced 200s, 300s, and 350s with TH400s, and never changed a drive shaft yet. No more cable to the carb, but you will need to set up an electric kickdown switch. A 76 should already have a place to mount the factory switch (still available) above the gas pedal. And a vacuum hose from the modulator to direct manifold vacuum. I find the 350 shifter arm linkage works on a 400, but a 200 does not. If you can find the right one, it will be simpler. I managed to re use a 200 shaft by changing the angle and length of the arm. Here it is. And don't forget to check the speedo output gear ratio. If your 200 set was off, you can make a correction at the same time. Easier to do on the 400, more teeth. I believe the 68 dip stick has an O ring seal. I found the late 70s style (with rubber funnel seal) easier to work with. Bruce Roe
short shaft, already holes in the frame for cross member, the 400 has the linkage still on it SMOKEY, the cross member is for dual exhaust SEAN, just put new mounts on the v6 posting a bunch of pics on x-bodys keith
