ktmrider

I posted 2 months ago but need to ask again.
Bought used 5.3L to replace my 4.8L. Decided to upgrade heads to LS1 casting 241's and stock LS1 cam. Do the rockers, pushrods, lifters, etc interchange? How about any recommendations on a cam? Last, who has the bearings, gaskets, bolts, etc? Thanks for any help!

Flem

actually you want to keep your stock 4.8/5.3L heads. they outflow the LS1 heads even with the smaller valves. If your going to do a supercharger they would be good as they have 67cc chambers vs. the 4.8/5.3L 61cc. If you run them stock you'll lose compression and flow w/ the ls1 heads. you can go to the internal engine and do a search on cylinder head flow, somebody there posted all the flow #'s for the stock LS1 based motor's heads 5.7LS1, 5.7LS6, 6.0LQ9, 4.8/5.3L(all engine codes the same.

ktmrider

Thanks for the info! I plan to stay normally aspirated but will hold on to the original heads if a swap to the Radix system happens. I was hoping the larger valves and higher compression would be a good upgrade ( see articles in GM High Performance Tech for LS1 ). They recommend the 241 heads and cam to get the truck engines moving instead of major flow work. I did not spend too much on the 241 heads tho in case we stay with the LQ7 stockers.

Slowverado

they don't outflow the LS1 heads, they just have a smaller combustion chamber that gives you a higher compression ratio. switching to the LS1 heads would give you lower compression(good for boost/nitrous) and it would also give you a bigger intake valve. as far as a cam, if you are already gonna be doing a cam(stock ls1) i would go with a comp grind or an 01/02 LS6 cam. i have an 01 LS6 cam sitting in my shop right now if you are interested. you can have the LS1 heads milled to get you back to or close to or above the stock compression ratio but i would go with those for the extra air.

ktmrider

Matt, I would be interested in the cam. Let me know what you want for it and the shipping to ZC 87114, NM.
Thanks for the great info and item!