if i were to buy used Ls1 heads on ebay, what should the casting number on the heads be?

also, has anyone else bolted on some Ls1 heads? Is it as simple as just bolting on?
i here it's about a 30HP gain, going from (not sure) 1.25 inch valves to two inch valves with the Ls1 heads.

 

241s if you are going to a ls1 head

 

FYI my friend...

https://www.performancetrucks.net/fo...d.php?t=402674

 

you have 1.94 intake valves in your truck heads... 1.25 is TINY!!!!!!!!!!!

 

like the title say i can get the heads and intake, haven't seen them in person but their from a good friend so i trust him, he says the intake has a small silver plate that says ls1 performance or something like that, what yall think, will this help my set up?

 

I thought the 5.3's had 1.89 intk and 1.55 exhst valves??

And wouldn't he need to get them milled???

And I wouldn't do the intake swap to an LS! intake..IN another forum WCCH flowed all of the different intakes and the truck intake flows better than the LS! if your going to do a swap atleast make it an LS6 intake.. IMO

 

Don't waste your time on the LS1 intake. Here is some hard data.