1964-66 C40 454 Swap? School me please.

[MrBeast]

Howdy heavy haulers!

I am currently looking at 3 trucks up in WA, They are c40's/50's.

One has an inline 6 in it, the others a V6.

I am wondering how hard of a swap it is to put a Newer big block in them? I know where I can pick up a 7.4 or 8.1 vortec.

Mainly concerned with bellhousings and motor mounts? I know that GM did some odd stuff back in the day like Chevy being one pattern, and the BOP being slightly different, not sure if the GMC V6 was the same or not?

If anyone has photos of motor mounts I would greatly appreciate them.

What my hope is, is to swap in the engine then put in a hydraboost and independent master cylinder for the clutch.

I had also thought a lot about swapping in an NV4500 if I can source one which would later prep it for a Cummins swap.

Throwing a lot of ideas at the wall right now and seeing what sticks.

The end goal is to wind up with a highway hauler which is also going to mean needing to swap out wheels. The C50 is a 10 lug, the 40's are that odd ball 5 lug?

Not sure if anyone has any insight here, but I do know that split rims are becoming persona non grata many places.

Any info you have to offer here would be greatly appreciated!

[Old_Green]

The years are different, so probably not the same, but I pulled a 250ci/465 out of a '68 C40 and a 350ci/465 our of a '72 C50. If anyone knows if they are similar, I may have pics.

[Pick121]

Welcome to Heavy Haulers!
First comment is, no matter what engine or trans you are running, if you are keeping the original 2sp rear end you will likely run into higher RPM at highway speed issues. They are just not geared to cruise at 65-75mph, something to think about.
As for a BBC V8 mating to a V6 or I6 bell housing, I am pretty sure they will not be a plug & play, others who know for sure can chime in. So, might as well do the engine and trans together. These trucks came with SBC and BBC V8 options so, as long as you get the right engine mounts you should have no problems.
Good idea to upgrade the brakes, the main point of danger is the single pot master cylinder. Good to upgrade to 2 pot MC

[MrBeast]

Originally Posted by Pick121

Welcome to Heavy Haulers!
First comment is, no matter what engine or trans you are running, if you are keeping the original 2sp rear end you will likely run into higher RPM at highway speed issues. They are just not geared to cruise at 65-75mph, something to think about.
As for a BBC V8 mating to a V6 or I6 bell housing, I am pretty sure they will not be a plug & play, others who know for sure can chime in. So, might as well do the engine and trans together. These trucks came with SBC and BBC V8 options so, as long as you get the right engine mounts you should have no problems.
Good idea to upgrade the brakes, the main point of danger is the single pot master cylinder. Good to upgrade to 2 pot MC

I am thinking of swapping to a later rear end for that reason, been looking at a few different options there, that is a pretty easy swap, been looking at an F550 axle set and swapping both to get the modern 10 lug pattern all around.

[dmb]

The bolt pattern on the bellhousing of the l6 and a 454 should be the same, There may be an adapter plate for a larger clutch and flywheel. I have no clue on the V6
This is free info take it for what it is worth.
David

[Bob B.]

The V-6 has a unique bolt pattern not shared with anything. V-6's in pickups with automatic transmissions have an adapter that mates the V-6 to Chevy-pattern automatic transmissions.

[MrBeast]

Originally Posted by Bob B.

The V-6 has a unique bolt pattern not shared with anything. V-6's in pickups with automatic transmissions have an adapter that mates the V-6 to Chevy-pattern automatic transmissions.

Good info, thank you!