JASON 77

iTrader: (22)

just purchased a MS4 from TSP, but if i go with there 5.3 heads do i have to flycut the pistons? if so maybe i can just do a MS3 and have them sink the valves little further. what do you guys think?

BOWTIE

They may be able to sink the valve enough that you will be able to get away with it with a stock gasket, but your DCR will suffer. For the best performance you need to flycut, then run a .040 gasket and maybe even mill the heads some to bring your DCR back up. Remember, the larger the cam you run, the higher the compression needs to be to make it perform right.

Beaflag VonRathburg

iTrader: (176)

Recessing the valves also hurts the flow of the heads. Flycutting is ideal. Set it all in place and check your piston to valve clearance. It's always the best method to check things yourself.

Phynix

iTrader: (3)

5.3 heads and ms4 = flycutting.

SOMbitch

iTrader: (8)

What I always thought too. MS4 will clear LS6 stage I (no mill) with stock MLS HG

99blancoSS

iTrader: (115)

I've been seeing this sinking the valves stuff in a few threads now. Must be flavor of the month time.

PREDATOR-Z

Sinking valves is a band-aid IMO and still doesn't offer "safe" PTV margins.
It will hurt flow, it also makes valvetrain uneven unless exhaust are sunk by same amount.
Yes it works, but IMHO it is not the best way to go about it. On the pro side it lets the boys stick that "big one" in, which is most of what they are interested in.

99blancoSS

iTrader: (115)

Yea I wont print what the builder said about it when I asked him. We had actually talked about this before but I've been seeing people either asking about it lately or telling people to have it done. You know how fads are on this site..LOL

PREDATOR-Z

Just marketing tools, same as putting 2.04 valves on a 2.02 seat

KCS

iTrader: (20)

Eat up valuable short turn is what it's going to do, especially on those 5.3 heads. May not be much, may make a net gain with the bigger cam but of the two choices I'd flycut.

Jpr5690

iTrader: (13)

Well Dam, It Must Have Been Those Sunk Valves That Limited Me To Makeing Only 430 Rwhp Through A Unlocked 4000 Stall

All Well Since I Didnt Flycut I Dont Have To Worry About Hotspots Or Cracked Pistons When I Spray

IF IT WAS ME ID ASK TSP (ITS THEIR BEST SELLING COMBO)