Originally posted by Chopper66:
Have been following this form. Want to put 4spd overdrive in a 66 C-10 250 6 Cyl. 3 spd. Does anyone know if a Chevy Np 4 spd. overdrive Transmission from a 6.2 PickUp will simply bolt in?
It did in mine. I have a '66 and bolted in one of these overdrive units behind a 292. Jam up fit. No mods. Even used the old 3 speed yoke. The only thing I had to do was find a "heavy duty" bellhousing (one with the 5 1/8 inch diameter opening). If you'll check out one of my earlier posts in this thread, you'll see a picture of the actual transmission I'm using. And that version of the New Process has the same bellhousing bolt pattern as any typical GM 3 speed/4 speed of the 60s & 70s.
Just know that there is at least one other variation of this transmission casting that has a Mopar-like pattern. If you get that one, then you have some work to do. First, you
must get the factory bellhousing. Otherwise the transmissions' useless. And second you
must use a rear crossmember because the factory bellhousing was the "circular" aluminum type (used in the 80s). You may have to remove the frame transmission crossmember for the circular bellhousing to clear. Your 1966 GM factory bellhousing has mount points cast into it to support the rear of the engine and the tranny. The circular bellhousing obviously doesn't. As you can see this begins to get quite involved if you don't find the transmission with the casting pattern like your factory box. I hope you can easily find the easy swap type like I found.
-magic mike-
