SBC to BBC, Th350 to Th400 in a C20

[FormerMember]

What are the gotchas?

I have new headers, externally balanced flexplate, Th400, fresh 454, torque converter, flexplate bolts, torque converter bolts, Lokar tranny kick down, motor mounts (poly), tranny mount (poly), tranny dipstick and 4 core radiator with cooler.

I've heard that I'll have to drill the towers for the motor mounts.

What else?

Oh and I swapped in a 1976 C30 front end, so the suspension should be up to snuff.

[Tx Firefighter]

Brackets and pulleys, power steering pump is different for a BB.

The Th400 uses it's own special yoke, so you'll need one if you don't have it already.

Be very aware, that you can put the 454 onto the small block mounts, but every exhaust I've ever seen hits the mounts. Big block mounts have a dish in them for manifold clearance. Seems like someone on here found a brand of header awhile back that cleared, but I don't remember who.

I wound up using factory big block frame stands to save the trouble. I use small block rubber part of the mount on the big block stands with no issues.

Notice the pictures I posted below, the exhaust fits into the droop in the engine frame stands. This could be the sticky on your swap, depending on which frame stands you use and how the headers fit.

[FormerMember]

Does anyone know if the 76 C30 frame stands will fit a 70 C20?

The headers I have are Flow techs. Supposed to be for ANY 2wd Chevy from 67-86...

We'll see. I may have to make omy own motor mounts and frame stands.

Have plasma cutter and a welder... can do anything!

[FormerMember]

Alrighty, I am breaking down and getting the towers from the BBC GMC I have in a buddie's yard.

Do you know if they'll interchange?