Don't forget, GMC's are about 3" longer than Chevies.
NP 540 series make great trans' for your application, I have adapted several to 4wd applications.
Ed
I’m decided to save the 302 for my 48 gmc 1/2. I’m getting 261 and 848 head machined right now for it, will have Edmunds 2x2 intake with Langdons carter Weber setup and some other goodies.I’ll have to swap a stock Chevy crossmember back in the frame because I modified the original to fit the gmc. These pics show what I did to the crossmember, I couldn’t resist adding one of my 302 I made the intake outa steel, it’s too heavy but hey it ain’t a race car. As much as I love the old SM420 4 speed im sure this 540 trans is going to be so much better. With the 3.07 rear gears I’ll be able to downshift to 4th and still maintain 55-60 mph
