420a head rebuild

[richi77]

well my 420a jumped timing nd im planing on having the head rebuild but i want some one opinion on port & polish with bore TB on a stock block with 8lbs of boost on a t3/t4. Btw its my DD so only want about 250hp nothin to crazy for now.

 

[bryanwheat]

For the airflow levels that you are running you will not benefit from porting the head or a bigger throttle body. Just get the head cleaned up with new valves and new gaskets and save your money.

 

[Fotowntalon]

I disagree on the TB, get a 60mm, with the intake ported to match, very common good mod for the 420a. As for your goals, isnt hard to hit with a turbocharger, but if you are rebuilding the head, some crower2's with springs and retainers is a solid investment. As far as porting the head, our stock heads flow rather well, unless you can get a hell of a deal, probably overkill.

 

[richi77]

Thnx for the info. One more thing is. After installing the turbo kit what else would i need to keep the engine from runing too lean/rich. Like injectors, Fuel pump, etc. Thnx for the help.

 

[Fotowntalon]

a way to tune it