ok what heads would be the best for a stock 305 i heard 416 and 081 but i also heard the 081 i will loose torque im thinking about doing what my grandpa said if it aint broke dont fix it...thats how confused i am.

 

Vortec

 

Vortec, or TFS Twisted Wedge.

The Twisted Wedge heads--LONG out of production, but still available used on eBay and such--were the only 2.02/1.60 heads that would clear the tiny cylinder of a 305. Even so, the exhaust valve would hit the wall if the lift was high enough--mid-.500s as I recall.

Been a long time since I read the article where one of the big magazines dropped Twisted Wedge heads onto a 305. I'm fairly sure the heads were the first-generation TW, not the second-generation. The second-generation may also work--I don't know.

 

TFS makes a head for 305 with a 1.94 intake valve.

 

Yes, TFS 175 would be nice too

 

I've had decent sucess with the 059 Vortec Heads (and they're cheap).

I would definitely do some work on them before installing, especially upgrading the valve stems to allow for more cam lift.

There are some Con's:

You'll need to buy a vortec compatible intake (I bought the GMPP TBI intake and it was a little expensive)

The Egr system will need to be deleted
--Or you can tap the driver side header, weld a the necessary fitting and buy the vortec specic tube that meets up to the port on the forward driver side of the intake.

I noticed lean pop after starting up cold (especially on a cold nebraskan morning)...So I bought RBob's EBL and tuned that issue away.

Overall, I'm pleased the 059's and they work well for a daily driver RS.