[RICK LAKE]

Mark M Mark jegs and summit both sell 6 spd Richmond trannys. Couple of things you need to know.
Input shaft, If using a lakewood bell housing, A GM input shaft needs to be check and possiblitity cut down .380". If this in not done, major damage to thrust bearing in motor. MUST check this measurement if using GM input. I have no info on Ford inputs. Quickbell housing my be different for depth and clearance of input to pilot bushing or bearing.
The trans mounting location is 1" farther back that most 4 spds. MY ERA was modified for this setup. Shifter is also 1" back too.
Again this trans is limited to 450/450 constant load power range.
Other 6spd are the T-56 trans used in Vipers and Vettes and "F" body cars. Again this trans needs to be beefed up to handle the power load. G-force will build one for your personal need. Again not cheap but 700/700+ load rate. Shifter also has a couple of different locations. It is longer and wider than the Richmond.
Ask Brent Bylkins for a cost. He may beat Jegs or Summit. You know we also have to look at clutches and what you want to run. Send me a phone # and good time to talk in the evening on a PM. The typing is wearing be out. It's alot of info. Rick L. Ps if you goto Jegs, then 6 spd trannies, this will give you breakdowns. Goto spec and get all the info you want for gearing. Stay away from any trans with 3.00 or higher in 1st gear. They sell 2.77 1st gear. This is an old 1st gear 4 spd box we used in the 70's and early 80's for 1/4 mile. We where using 4.56 to 4.88 rearend gearing. It will move any car quick with a 3.55 gearing.