Finally, my first 360 and goals for it! I'll be asking a lot of questions.

trebor75 said

How come Comp Cams says the XE268H and XE262H requires adjustable Valvetrain!?

Click to expand...

It says that down by the lifter choices. If you use a stock type lifter stock valve train will work, if you buy the optional anti pump-up lifters adjustable valve train is required.

Those cams are too small to need anti pump-up lifters IMHO.