[Blown353]

Make sure you have adequate driveshaft clearance to the tunnel with the driveline / u-joint angles properly set and the suspension at full bump travel. It would suck to get the car painted and start assembling and then find you have a clearance problem.

It's probably been 15 years now, but I had to slice out and raise the tunnel on my car from the firewall all the way to under the rear seat to have proper u-joint working angles and good driveshaft clearance at full bump travel, plus a bit more clearance for safety at my low ride height. I know Roadster Shop sets their frames up for low ride heights so it might be an issue on your car as well.

Didn't help I have a 4" driveshaft and was shooting for the absolute minimum working angles on both u-joints (about 0.7 degrees, just enough angle so the needles would spin to avoid flat spotting)-- that meant the transmission tailshaft had to go quite high and also had to angle the rear end "nose up" quite a bit.

Of course, with single and double CV driveshafts now being available you have a potential workaround if you need a little more driveshaft clearance and don't want to cut the entire tunnel out-- you can run increased (and mismatched!) working angles compared to standard u-joints and not have any vibration concerns.