I just installed my 5.0L into my '66. What headers will fit, and will I need to modify my shock towers? Not looking for street legal, going road racing.

 

Anything that fits a 289 in a 66 will work, the blocks are identical in that respect. You won't have a mech clutch linkage on the block without a bracket for it, but long tubes + z-bar clutch is a pain to adjust. Hooker Super Comp long tubes(or equivalant)would be good for what you're doing, but if it's a bumpy track you mayscrape if your suspension isn't uber-stiff so you might wanna do shorties too. Cable with a 5 speed or a hydraulic linkage for the clutch would work well with long tubes.

 

Not a problem with the clutch linkage. I installed a T5 and ordered a tranny cross member and cable linkage ($$[sm=outcold.gif]$$) from Modern Driveline.