Thread: 350 - 6 cyl interchange

Tweet

hey guys,
i have a 83 GMC 1/2 ton pick up that i just put a 350 w/ forged pistons and a crower solid lift cam and valve train, cam specs are intake 284 ehx 296 adv. dur 504-504 lift. i also have a bone stock 79 chevy 1/2 ton that has a 6 cyl with a 3 speed on the column it came with a 12 bolt posi rear end. i want to take the 3 speed out of the '79 and put it in the 83 GMC and install a floor shifter.
Questions: will the bellhousing off the six fit the 350? will the flywheel off the six fit the 350. since the 83 is automatic i believe the clutch pedel out of the '79 will bolt right in the 83 along with all the clutch linkage? will i need the crossmember from the 79 as well as the drive shaft? i plan on installing the 12 bolt from the 79 and disgarding the limited slip 10 bolt from the 83.
any other interchange info would be helpful.

thanks

Hey hemi hunter, I'm not sure how many versions of that 3 speed they made, but I don't know that it would be strong enough for that 350. Ofcourse that would depend on what you are doing with this truck.
My buddy restored a 77 chevy stepside and when he went to get an estimate on getting the 3 speed rebuilt, the tranny guy told him he would probably break it. He was running a very mild 400. He ended up just converting it to a turbo 350.

good luck, josh

I believe the bellhousing will swap over. I doubt that the three speed will stand up to the warmed over 350 for very long; however, a 4 speed Muncie or a T-10 out of a first generation Camaro or Firebird, or a Chevelle or other mid-size, or a three speed from a Firebird will bolt right up to the bellhousing, and should be the same length as the three speed you have, and same output shaft splines. An easy swap.

I ran a junkyard 3 speed that came from a 66 Chevelle 6 banger behind a mild 400 sbc, Isky 30/30 cam, headers and 650 dp with no problems in a 62 half ton. I had a 3100 lb pressure plate built for that combination and ran it with the stock hydraulic clutch mechanism. I did go through 3 stock rear ends though.