any one have their heads done lately what did they cost? and what is the largest valves you can run? and is 290hp naturally aspirated possible. if so what will i need. ooo. and what is the highest a stock 700r4 can handle?

 

Head porting varies by the shop. A local guy just doing it as a side project for people he knows would do mine for $300. Others on here have paid nearly a grand.
I've seen the valves mentioned on here, but it was a while ago. I'm sure someone will chime in with "search".
290hp is possible, but not for cheap. That will be a very high rpm engine, and I don't think the iron heads flow well enough to make it there. Aluminum heads, fwd intake, and aggressive cam should make around 300 hp.A healthy 700r4 should be able to take a 300 hp v6.

 

thanks, im just thinkin about the route im going to do naturally aspirated or mild turbo.

 

just make sure that 700r4 is healthy, or youre gonna rip it apart. most guys who have put a good amount of hp to that trans, say goodnight fairly soon. while i have a manual, id say if you have about 100k on the clock or if youve been hard on it/no maintenence, get a reman or rebuild it.

 

300 hp has been done with iron heads before, but only with extensive porting, huge cam, lots of compression and a manifold that's not made any more. You'll spend alot more trying to get the iron heads to 300 hp than it's worth. Turbo it.

 

u can only go slightly bigger on both the intake and ex valves due to the spacing of them.
not worth it except on a max effort engine

at minumum at 300 hp u will need a shift kit in the autotrans, and i would also suggest a servo kit