Ok, now I'm down to the wire. I have ported, polished, bowl blended and gasket matched the 336 x 76cc smog heads. I have 2.02/1.60 and 1.94/1.50 swirl polished valves from Powerhouse. I also have a set of 416 castings currently into my modded 305 HO (1984 Z28). Would it be a better choice to just port and polish the exhaust, bowl blend the int/exh, and mild or no gasket porting the intake. (Is porting the intake port worth the results or the loss of velocity?) Both being modded with specs above, screw-in studs, 1.6 roller tip rockers, CC XE268 cam (.509/.512 corrected lift), which head would best perform? Also, can the 1.6 valves fit the 416 head? 1.94/1.6 sounds nice, but not if it can't flow. Any help is appreciated.

 

Is this for a 305? If it is the 416 are a much better choice.

 

Great! You are exactly the person I wanted to ansewer this question. I tried to email you this, but it didn't work. The 305 is currently in the Z28. This is for my 350 bored 0.060. I have a bunch of new and slightly used parts from previous engines. Now, it doesn't matter if I use the 336x or the 416 heads, I'll still have 9.5:1 CR (two sets of pistons) What I really want to know is which one in modded form will make the most power. Figure this: both are ported, polished, gasket matched, bowl blended, and the casting flash has been taken out of the chamber by the same person. One has 1.94/1.60 and the other has 2.02/1.60 (You know which valves go to what). Now which one makes more power on my 350? The only reason I said this is that I spoke to the machinist at NAPA in Warner Robins and he said the 416s were a better choice for what I wanted to do (Street only). Reeves performance, also in Warner Robins, told me the 336x would be fine in stock form with just a 3-angle valve job. That in itself sounds fishy, so I wanted to ask you.