ok any head recommendations looking to go rectangle port heads because of a future lsa blower

 

You can't. Square port heads only fit 4.00" bores or bigger

get the 706s ported and 2.0 valves put in them

 

LS...life was so simple then. WTF was I thinking

 

if you are hell bent on buying heads. Im running the trick flow gen x head. Im running the 225 on my stroker but a 215 might suite the 5.3 better. I personally think you should run stockers, get long tubes and if you go boost just run it. Dont overcomplicate it and if you choose to….. do your research.

 

oh. Run a tvs 1900 on those cathedral heads

 

Not necessarily...

 

the thing is the truck likes to back fire and struggles starting with regular 91 without additve

 

Just run the stock heads if your going to put an lsa on it. Heads make basically zero difference if your boosted. Bump compression and roll with it.

 

Sounds like you need a better tuner

 

I think you need some tuning since octane and starting really dont have anything to do with each other.