Byter

iTrader: (1)

The gaskets may be ok but the headbolts (I assume they're the GM ones) cannot be reused. They are torque-to-yield, and if you torqued them according to spec, they stretched. If you have the money, get the ARP studs and you will never have to worry about it again, plus, they are easier to torque down.

CNTLSE 1

iTrader: (11)

curious also about to do the same install. Keep us posted

cjh

iTrader: (4)

Thanks for the all the info. I will contact TSP tomorrow regardingin the pushrods before I pull the head (last resort) and clay it, I do have the ARP bolts so I can reuse them. To the question where is the resistance is occuring, I start with TDC on #1 and it starts to resist just a bit after i begin to start to turn the motor.

ssfast99

iTrader: (3)

if that is the case then you need to clay the nember 6 cylinder if i think right. anyways also the statement about the .012 clearence not enough, when you install a big cam and 243 heads non milled .012 has to be fine because if you use a bigger gasket the compression goes down. no use with a MS4 with 9.2 compression on a NA car. are these your first set of good springs that you have experienced because the extra pring rate could be messin with your head. a good spring could make it a little harder by hand to rotate.

cjh

iTrader: (4)

This is my first experience with double springs, so I have thought it can be because of them. But there is more resistance with the intake valve then the exhauset valve, can this be attribute to the cam lift specs?

NHRAFORMULA00

iTrader: (2)

when you pull the head off ,look at the piston for valve marks in it.sounds like you might have a clearance problem.maybe those heads have been milled too much by mistake. im only guessing,call tsp .they will help ou out.

4U2BNVS

iTrader: (2)

Hey I just got the same set-up and texas speed told me to go with the 7.4 pushrods. Talk to them at least twice a week. If they're the stock head gaskets they're .052 just to let ya know. Should clear just fine

ShevrolayZ28

iTrader: (4)

ARP bolts are re-useable but GM bolts should not be re-used if they have already been torqued. And I don't think you should re-use the graphite gaskets either. It would suck if it leaked. They're cheap, replace with new IMO.

-=Modified=-

iTrader: (3)

Will the crank rotate past the point you are at? If so you are building compression. Rotate the crank one full revolution and post back up with results. The rotation will get tense then release once you hit exhuast.

RZRSEDGE

iTrader: (21)

http://www.gmhightechperformance.com...onclusion.html
Not to argue about the milling or the pushrod length, just so you all see where I got my info. I don't know what may be causing this, but I would want a definite answer before firing it up.

cjh

iTrader: (4)

I spoke to TSP and confirmed that 7.40 pushrods are good and that these heads actually have a tiny bit more PTV clearance then stock. So shouldn't be a problem. I double checked my dot to dot and everything is good. I think I was just a little paranoid since this is my first H/C swap. Couple of other reasons I am going forward:

1. Researching same combo does not indicate others had same issue
2. Can not hear any metallic touching
3. Can continue crank rotation past point of resistance.
4. Resistance begins just a bit after TDC of #1, piston on way down and intake valve opening and resistance stops once hitting exhaust.

You might be saying to check to ensure, but I feel very confident and in the end its my call. I will let you know what happens.

RZRSEDGE

iTrader: (21)

I REALIZE that it's your call, you asked for help and this is what I offered. I'm not trying to tell you what to do just help!

DirtyJohn

iTrader: (8)

If you have time, might want to give installing ALL the rockers a shot and turning it.
Mine did the same exact thing with only a couple rockers installed.
I was worried I screwed something up, ALOT of resistence in only one part of the rotation.
Installed all rockers, smooth as butter all the way around.
There's mechanics involved that tell me this makes sense but I'd have to stop and think about why.
I think it has something with the concept of why stronger springs don't make it harder for the cam to spin, something about when one's compressing another is expanding.

Just a thought, or half a thought.

cjh

iTrader: (4)

Sorry if I sounded negatively, didn't mean to. This is a the best site for information and understand other's experience.

bayer-z28

iTrader: (14)

We just did this install on -=Modified=-'s car. He has a nasty valve tick after install w/ (stock thickness?) GM gaskets. We found out that he needed 7.425" push rods.. After the rockers are torqued, give the pushrods a wiggle. If you have play, they might be too small. They should spin a little when that cylinder is at TDC on Compression.

Just my $0.02

RZRSEDGE

iTrader: (21)

No problem!

99M6Z28

iTrader: (8)

let us know how it all turn out!

cjh

iTrader: (4)

update

i used checking springs and cranking the motor by to check ptv, reasoning being cause i havent seen anyone with ptv issue so i was just double checking.

started right up, oil is up to around 60 psi and left it running till operating temp. i have open headers and it sounds insanely mean . have to take it to a shop for true duals with flowmaster single chambers and tune.

thank you everyone for you help and patience. if only you can see the grin on my face.