Pay attention with those Comp 914 springs. They only work on Krabben's motors because it's a 454HO crate engine with old school rectangular port heads- traditional 1.88" spring installed height, non-rotator/retainers and a partridge in a pear tree. (They were a Team-Damon special selection to fit his specific application as a drop-in upgrade) I have NO IDEA what the spring installed height is on a factory L29 head. If it's 1.88", and the factory spring pockets can accomodate them, they'll probably work just fine for you. If it's not, you could be asking for trouble. Valve springs are HEAD-SPECIFIC as well as cam-specific if you're looking for drop-in simplicity.