Krab

iTrader: (28)

I was looking at TSP's LS6 heads ( ported by PRC) and the standard valves are 2.00"/1.55". To upgrade to 2.04"/1.575" valves, it costs $400. So I go looking around for larger valves on another website and come up with Manley valves 2.055"/1.575" for about $110 per set (intake or exhaust). Would anything else need to be changed if I were to buy a set of the LS6 heads with the standard valves, buy the Manley valves and swap them in myself? Does there need to be any work done to the heads for the larger valves? One last question, is it worth it to upgrade the valves, or just stick with the standard valves on the heads?

orangeapeel

iTrader: (18)

The valves will fit but they will have to be lapped for one thing or they will not seal properly in the cc.

Krab

iTrader: (28)

Gotcha, I knew it wouldn't be that easy. So is the valve upgrade worth the $400 hp wise?

Xtnct00WS6

iTrader: (8)

What he said. If you get anything bigger than stock valves, they'll need to be opened up a bit (valve job).

I believe that 2.02/1.57 is pretty much the optimal size for stock cubes. You also don't need new valve seats for the 2.02/1.57 size either. Anything bigger I think you'll need new seats put in.

Jon@Texas-Speed

iTrader: (18)

The 2.04 1.575 combo fits in the stock seats with no problems For the best possible flow with stock seats this combo is very hard to beat. We're putting together a run of those stage 2.5 LS6 heads right now. They are on special for 1499 with springs & 1250 without!!