guys, i have some stock 98 ls1 valves here that came off my TA. I also have a set of stock 5.3 spare heads im gonna work with and do a lil port/cleanup job, valve job, and mill them slightly for CR reasons.

Would the ls1 valves have to be worked to fit? Or do they just drop in?

or would I be better off going with a set of manly 2.0's since stock 5.3's have 1.89?? Any need for the exhaust valves also since they are allready 1.55?

 

Stainless valves are pretty cheap off of Ebay... If you were to do any work on those 5.3 heads, I would suggest just buying new ones in 2.05, 2.08, or 2.10 intake and 1.60 exhaust to make it worth all of the trouble. As you stated, the stock intake needs to be opened up for the 2.00 LS1 intake valve size.

Just for reference... I got my 2.08/1.60 back cut stem swirl polished stainless valves combo for $75 on EBay, along with brand new 5.3 heads (assembled with stock hardware) for $250...