ss.slp.ls1

iTrader: (36)

My first post in this thread is what Ai uses in their 200cc LT1 ported heads. They must use them for a reason.

96capricemgr

iTrader: (1)

Explain that replay to me a little please. How does my post have anything to do with your's?

My reply was in response to andysc's blanket statement about valve weights and the apparent assumption that 1.600 would work in stock seats.

I know what AI uses and I know why.

ss.slp.ls1

iTrader: (36)

I was saying that they use 1.56" exhaust valves, so when you say that 1.6" exh valves might not fit is probably true. I was trying to agree with you, not disagree.

96capricemgr

iTrader: (1)

gotcha

Z-RATED94

iTrader: (6)

The 1.60s would require a different seat, the 2.00 can have the stock seat cut to match up.

GIZMO

iTrader: (8)

The first thing that I would do is dump the 561 heads. I like the Manley valves and have had good luck with them. Depending on your total build going to bigger valves might not be the best idea unless you do a bunch of port work. The stock 1.94/1.50 size will support a lot of HP. There are Super Stockers running well into the nines N/A with stock size valves.

GIZMO

iTrader: (8)

If you do decide to go to bigger valves you might want to run LT4 valves. They are 2.00/1.55. They are expensive, but very light.

ss.slp.ls1

iTrader: (36)

Hmmm, are they a direct swap?

GIZMO

iTrader: (8)

Any time that you go to a bigger valve you will have to open up the seat/bowl/runner to match.

myltwon

iTrader: (1)

from what I've heard there is little benefit to larger valves in your average stock cube motor and can lead to valve shrouding

madmike9396

iTrader: (29)

So i would be best just to stick with the stock valves and just new ones the same size