XFiveLiter

I'm tryin' to make a decision, need some input. Just looking for some before/after dyno numbers and track times? TIA

Beast96Z

iTrader: (21)

Both the 5.3 and the 5.7 have the same port design. You will gain some extra compression with the smaller chambers of the 5.3, which will add a little more power. With your mods and a A4 you should be close to the 390-400 rwhp range with these heads.

gomer

iTrader: (13)

Before going to the big cam and LS6 style heads, I ran a set of the 5.3's and a TR220 cam. It made 416rwhp 392rwtq with all bolt ons and stock tuning. On street tires it ran a 12.28 @ 117mph around 3,550lbs and a 2.1 60ft time.. the DA was pretty high down here this summer when I did that. It is hard to beat those 5.3's for the price when using a smaller cam.

ssheets

iTrader: (1)

I've been doing similar research. As stated above, the ports on the 5.3 and 5.7s are the same designs. The 5.3 is (I believe) 60cc while the 5.7s are 66.67cc. So you can run the higher copression on the 5.3s without worrying about piston to valve clearance so much.

I was told by PP that the LS6 style heads are better with really big cams. I'm looking at 224 to 228 duration so I think I'm going to go with the 5.3 stage IIs. Since the PP LS6 style heads are welded up 6.0l heads they can set them up for what ever CR you want.

...too many decisions.

Hope this helps and keep us posted with your results.

XFiveLiter

Thanks for the replys. I think I'm going w/the 5.7s milled .030. I got quoted a VERY good price on the '98, perimeter bolt, 5.7s (low price not available on 5.3s).

W/my small cam and the milling, I shouldn't have any PTV clearance issues, should I?

I dynoed 370rwhp, cam only. I would be satisfied w/400rwhp, I think that would get me into the 10s (3250 race weight) in good air.

onyxxtreme

iTrader: (4)

oh yeah, I believe i was told the perimeter bolt 5.7's were $300 cheaper than the centerbolts
i went ahead and got some centerbolts, cause I want aftermarket valvecovers in the future