so ive been doing some research and its a very mixed bag of opinions BUT most of those post are from 5 years ago or more. i have a set of 862 5.3 heads with the smaller intake valves.

is it worth it for me to purchase a set of 243 heads and get them ported?

or

should i just use the 862 heads i have laying in the garage and get larger valves installed and ported?

i cant seem to find actual flow numbers between the 2. (i know flow numbers dont tell the entire story on power output)

i am not so concerned about peak power. i really want a easy to drive daily driver with a nice power curve and great throttle response. my goal is about 400rwhp on a gen3 ls1 with ls6 intake manifold. i would rather not make that power with a large cam.

 

I run the 862 5.3 heads, and with mods in sig, my car runs pretty damn strong for what it is! Enought to run neck and neck with a ported/pullied 03 Cobra. I'd keep those heads for sure

 

862heads will do a good job. If you can get a good set of 243s for a good price get them.

 

anyone have any idea how much it would cost to get larger valves installed on the 862s and get them ported? any company you guys recommend to do the work on the 862s?

 

anyone else with real world experience with both heads?

 

Call texas speed! they do both heads and got great customer service. Im running their 5.3/2.5 and TV3 cam and love it.

 

Its hard to say on pricing. But just guessing condidering their head cam kit is roughly 1200. You may only be out a couple hundred bucks for the head work. When I ordered the kit I asked about the hp difference between the 5.3 and 243 and was told under 15hp at peak. So for the price I went the 5.3 route since you can still make over 400whp with the heads

 

great. ill have to give them a call. if i can make about 400 rwhp for about 1500 bucks i may just stick with the 5.3 heads. it will be more about power under the curve vs peak power for me. i know these motor can make a lot of power with just a cam swap. but i want good power throughout the entire mid to high rpm range.