Currently the runner length is 5-1/2". I'm concerned about clearance in a FWD car. If anyone has a measurement from the firewall to the VE head (mating surface of the intake), that would help alot. We are not big fans of the delrin spacers, so we'll stick to the o-rings. We are in the process of making a die for 4" plenums. That's what we'll make for the turbo cars w/ the Q45 TB. As far as the NA cars, we'll have to do more testing to figure out what works the best.
Mark