jpgolf14

Guys,

I am swapping an LT1 T-56 into my '87 Camaro.

I understand the LT1 pressure plate uses special bolts with an extended shoulder. The shoulder is designed to go all the way through the pressure plate and slightly into the flywheel. Based on pictures I have seen, the stock flywheel seems to have a counterbore for the shoulder to fit.

I have no stock parts to compare. I have the SPEC steel flywheel, SC85S. It does not have a counterbore for the bolt shoulders. The SPEC does come with standard grade 8 pressure plate bolts, but common sense tells me GM designed the extended shoulder for a good reason. What are people's thoughts on this? Maybe SPEC forgot to dill the counterbores on my flywheel? Do others have aftermarket flywheels with the shoulder?

There are pictures of the bolts and the stock flywheel counterbore here:
http://www.zr1.net/forum/showthread.php?t=8306

Thanks,
John

SPEC-01

iTrader: (2)

Your flywheel is not miss-machined and this difference in the shank length will pose no issue relative to fitment and/or function. We have sold thousands of these without issue. Simply use the bolt provided and let me know if you have any further questions. Thanks and have a great weekend!

jpgolf14

SPEC,

Good to hear. It is just funny to see all the discussions on the net of the special bolts when you guys have them.

88silvergt

iTrader: (8)

Now if we can get spec to sell the bolts seperately...

BALLSS

Does the SPEC bolt look like the pic below?

and the stock FW does have a counter bore

SPEC replies their FW & bolts do work

Jessman

I know this thread is old, but i just had an issue with a spec stage 2 clutch install and wad using ARP lt1 pp bolts. The pp didn't mount flush even though the bolts appeared to torque down and caused the clutch to slip.

I'm assuming Spec machines the pressure plate down a little where it mounts to the flywheel so it has greater clamping force.

SPEC, are your supplied bolts shorter than stock GM pp bolts? I bought my clutch used and it looked almost brand new. I'm guessing the last guy had the same slipping issue and decided not to mess with it.

Need an answer pretty quick, car is still torn apart airing my solution to getting everything mounted flush.


Also, i see no evidence of a balance mask on either the spec steel flywheel or the stage 2 clutch. Are there supposed to be balance marks that align? and if so, pics please.

SPEC-01

iTrader: (2)

Jess, I replied to your PM (in a couple of parts due to being rather busy on this end and not getting everything in the original response) but wanted to post here as well for others with similar questions. You note using ARP bolts. Is the clutch being held above the mounting surface by the shank of the bolt? We provide bolts with our flywheel and I can either supply dimensional info or sell you a set of bolts separately. We do not machine the pressure-plate mounting surface to change its depth. My contact info is below if you'd like to contact me directly. Thanks!

guppymech

iTrader: (7)

The bolts that came with my Spec billet FW have a .500 shoulder which is less than the stock or ARP LT1 PP bolts. As noted, the Spec FW bolt holes for the PP are not counterbored for the shoulder of the stock or ARP bolts. I don't know why Spec omits this minor machining step to allow the PP bolt shoulder to fit into the FW which IMO provides a stronger assy. I counterbored the bolt holes in my Spec FW to allow the use of nice ARP PP bolts. Any machine shop could do it.