: 1977 k20 with 500 cadillac engine Exhaust manifolds

02-26-13, 01:26 AM
I just got a k20 with 500 Cadillac engine. Want to stay with stock exhaust manifolds but the passenger side hits the frame. Does anyone know what manifold will clear the frame? Thanks.

02-26-13, 10:00 AM
The 425 right exhaust manifold has a downsized #1 cylinder runner for this purpose on the on the 1977 - 79 cadillac frame. I wouldn't be surprised if the k20 didn't share the same front frame section. You can also trim the upper control arm around the front bushing round to prevent heat transfer, just don't get too agressive with it .

02-26-13, 10:20 AM
It hits at the collector .

02-26-13, 06:07 PM
Sounds like a nice rig. I do some towing with my k10 and have been contemplating a big Caddy engine swap myself. Let us know how you get the manifold to fit.

02-26-13, 09:57 PM
Check the this post:

One of the guys just swapped a 500 into his 64 C10. I think he was making custom mounts, though, so the engine probably sits higher, but he's using stock manifolds. How bad is yours hitting? Can you clearance the manifold with some grinding? How about heating and denting the frame?