# 1974 455 with a 4l80e trans



## Geoman340 (11 mo ago)

Hey group I'm planning on putting a 4l80e in my 66 lemans with a 1974 455 with 96 heads. I'm doing some research on what I need to make this happen. I know I need a computer and adapter plate to bolt it up to the 455. Can I use the same pontiac flex plate and starter? can I use the torque converter that came with the 4l80e? The trans came out of a 2003 chevy express with a 6.0. Thanks in advance for the help


----------



## lust4speed (Jul 5, 2019)

We just installed a 4L80e in my '65 Catalina Safari. Engine is a 455 stroker and we used a Pioneer SFI 400 flexplate and the IMI starter that was with the engine before converting to the new trans. Now the unknown is that we used an aftermarket converter that had multiple bolt holes for hooking up to the flexplate - so I can't say for sure that a pure stock converter would attach to the flexplate. The trans was the later 97+ model so it had the return hose fitting at the rear of the trans, and the 90° aftermarket banjo fittings were necessary. Everything I've read says the trans goes right into the A-bodies, but we had to expand the tunnel quite a bit on the B-body. Now I know two things that I like better with our A-bodies, the larger trans tunnel and the wider rear wheel tubs.


----------

