78 gmc 6500 366 r&r

[67JimmyMO]

I am wanting to R&R the 366 in my 78 GMC 6500. Pulled the radiator, exhaust manifolds (left the exh pipes attached), starter, hoses, wires, etc.

Then went to remove the bellhousing-to-engine bolts. There are 7 3/8" bolts that hold the bellhousing to the engine... and it looks like the bottom 2 and the top one are inside the bellhousing, with about 1/2" clearance to the flywheel. I don't think I can remove those 3 bolts without removing the flywheel.

Was wondering...am I going to have to remove the engine/bellhousing/trans as a unit to do the engine R&R? Or pull the trans, then drop the clutch and flywheel out the bottom...then remove the 3 bellhousing-to-engine bolts that are behind the flywheel?

I've done a lot of engine swaps on cars and pickups but not so much on these bigger trucks...this one has got me stumped on the best way to proceed.

[67JimmyMO]

With a little more investigation it looks like there is a 1/4" plate that is between the bellhousing and the motor...and may be the inside bolts I am seeing just hold the plate to the motor.

And I think I did find the top bolt on the outside of the bellhousing that I thought was on the inside..

Is that 1/4" plate an adapter plate to allow for a larger clutch possibly?

[jumpsoffrock]

^I have just found out recently, that that is exactly what it is.

[mrolds88]

Yes. Plate bolts to block and bell bolts to plate. You should have a 13" clutch.

[67JimmyMO]

Thanks for the replies jumpsoffrock and mrolds88.

Was sure hoping I could pull the engine without pulling the trans or bellhousing, glad to hear that is the case.