XLR8NSS

iTrader: (4)

Check the last post in this thread out. Physically they MAY fit but, it would be mighty close IMO.

https://ls1tech.com/forums/showthrea...ght=vavle+size

Best thing to do would be to call Terry @ Patriot or someone who builds motors for a living to get a better answer.

Ryan23silverado

iTrader: (1)

Um, they fit Don't ask me how I know...This is the LS6 'style' head with 2.02int and 1.57exh valves.

BigTex

iTrader: (16)

Maybe they physically fit, but I bet the tight bore would hurt air flow.

You'd be better off seeing if TSP will swap them for a set of custom stage 2 5.3 heads with 2" intake valves.

Ryan23silverado

iTrader: (1)

BigTex, you have a good point -and it is true (for NA) You don't want a valve so big that the cylinder side wall becomes a restriction from intake air hitting it right out of the hole. If you are Boosted...force as much as you can in

Slowverado

okie, send me an email at slowverado@yahoo.com and i'll see if i can help ya with those heads. maybe we can figure something out.

01Sierra

so is there any final consensus on if these heads will work on a 5.3??? I wanna put a set of LS6 headson mine too, and this was getting interesting.

Ryan23silverado

iTrader: (1)

Yes they fit.
If you are NA, you will want smaller than a 2.02 intake valve if using the heads on a stock bore 5.3L

01Sierra

alright then, how bout this?? Could i take my stock heads and bore them out to LS6 specs???

Ryan23silverado

iTrader: (1)

maybe i was confusing...but you bore blocks not heads.
I would just ask Terry if he could install smaller valves in his heads to accomodate a 5.3L engine block bore diameter.

01Sierra

Ooops, wrong wording sry bout that. I mean port my heads to LS6 specs, lol.