why is it that every place i have taken my heads has told me that it is not possible to port my lt1 heads to 202 160 they say that its not possible with out running in to problems and thats where the leave it if this is true what extra needs to be done to the heads to fit these valves or do i need to look further for a machine shop?

 

Your stock aluminum LT1 heads have an induction hardened valve seat fit into them which was designed for the stock 1.94/1.50 valves. These existing stock seats can be "opened up" during the course of a good competition valve job to accomodate larger 2.00/1.56 valves. That is, the STOCK seats can be machined approximately .060 over. To use 2.02/1.60 valves with the idea of getting more flow, you need to REPLACE the stock seats, and this requires 1) removing the old seats, 2) machining the heads for the bigger seats, and 3) shrink fitting the new seats into place. The cost for doing this, (just replacing the seats to use 2.02/1.60 valves), is usually in the neighbor of around $450 to $550 dollars at most good machine shops. Add to this the cost of the valves, valve job, springs, retainers, etc.etc. AND porting; and you will EASILY have over $2000 into these LT1 heads. And, for that amount of money, you're just better off looking at LT4 or aftermarket heads, where you'll find more "flow for the buck".

Hope that answers your question?

Oh yeah, this question should NOT have been posted in the "For Sale" section, by the way.