I have a 64 Chevelle 2dr hardtop bench seat, column shift. I'm currently replacing the floor pans in it and I'm thinking of doing a 6 speed with my LT-1 swap instead of the 4L60E I have now. What kind of Work will need to be done to the Floorpans if I put a 6 speed in? Is it as simple as cutting a hole, or will the trans tunnel have to be cut out and a new piece welded back in?

or will the trans tunnel have to be cut out and a new piece welded back in?

Yes.

There is a guy here who did a T-56 install in an El Camino... he got away with minimum tunnel modification. It is highly likely that you'll have to cut the tunnel out. Check out the cardomain link in my signature block to see pics of my T-56 tunnel surgery.

-b

I put a D&D Performance six speed in my 66SS, and it was not as simple as the 64 mentioned here. I ended up with some floor and tunnel surgery that had to be repaired by welding in curved panels to obtain floor clearance for the upper side of the tranny. In retrospect, i wish i had replaced the body mount bushings first...would have given more clearance and probably not required all the cutting and welding.

i raised my tunnel up about 1.5" to clear the T56

Thanks for the info everyone! It sounds like I'll need 1.5-2" higher. I think I should have that much extra. When i cut out the old floorpans, I left an inch or two below my line where the new floorpan will go. I've heard you set the transmission at 3degree angle? Is this correct? If so, what surface do you check the angle from?

I've heard you set the transmission at 3degree angle? Is this correct? If so, what surface do you check the angle from?

anywhere between 3-5*...oil pan, balancer, tranny tailshaft etc....