CNTLSE 1

iTrader: (11)

So I am installing the PRC 227's to go along with the MS4 already in the car. I measured for pushrod length today and its good kinda between 12 and 12.5 turns. so if I go with the 12.5 thats a length of 7.425 before the preload. Just thought that seemed kinda long. What liength pushrods are others running with these heads? I will call TSP tomorrow hopefully. what preload should be ran with these also? Thanks

bayer-z28

iTrader: (14)

^ IIRC, stock is 7.5. So that may be right on the money. My buddy is running 7.350's on his MS4 also. Depends on your head gasket too.

The PRLC doesn't lie.

If you feel like doing some side reading.. i got my info from here. (this page has PR sizing info)
https://ls1tech.com/forums/generatio...preload-5.html

ct06gto

As stated, the 227's have a thicker deck. A .1 longer pushrod is needed. So 7.5 is spot on.

CNTLSE 1

iTrader: (11)

ok well that make me feel better. I got a little worried when the 7.4's that I ran with the PRC LS6's were way too short. Good thing I measured. lol Thanks for the info guys

ct06gto

Yup, preload for ls1 lifters is .05-.08.

1madss

iTrader: (10)

I have the 237s, but I would think the deck is the same. I tried 7.45, giving me .045 preload. I went up to a 7.5 for a preload of ~.075 with LS7 lifters.

CNTLSE 1

iTrader: (11)

ok sounds like a 7.5 is about standard with these heads then. I got busy at work today and didnt get a lunch break to give TSP a call. Maybe tomorrow

Jon@Texas-Speed

iTrader: (18)

Those heads will require a longer pushrod. Depending on milling options, you should need 7.450-7.500. From what you are seeing you are correct. Let us know when you're ready for them and we'll get you fixed up!

Jon

Jason 98 TA

iTrader: (4)

Let us know how those thing run! I've been building them like crazy lately & they're always making some big hp! That without a doubt is the best all around cylinder head for the LS1/LS2 cathedral cars.

CNTLSE 1

iTrader: (11)

will do. Gonna be a bit before I am all done. Its a slow build for me lol

chrs1313

iTrader: (24)

you think these will gain over my TFS215s...

Wondering if you have results you can share to prove that statement...not doubting but I have seen only average results from the PRC215s...

thanks