I searched this topic, but the most recent post referencing the issue was a bit dated.

Does anyone aftermarket make flywheel bolts for the LT1 engines, or am I limited to buying through GM?

Also, aside from my local dealer or maybe gmpartsdirect.com (which I have heard is sloooooooww to ship) is there an online source?

I need some this week. The guy I bought my swap parts from gave me five correct bolts, some with chewed heads, and one bolt that is too short because it's for a flexplate and not a flywheel.

 

What I've done in the past, is purchase two ARP torque conv bolt kits (230-7303) that have a smaller head that clears the 1pc RMS, and still has the correct threads and UHL.

YMMV

 

Thanks for the reply and idea, Mike.

How do the heads on the torque converter bolts compare in size to the factory flywheel bolts? I wouldn't want to go too small, if GM intended for them to be a certain size to spread clamping force.

 

Smaller in relation to the ARP flywheel/flexplate bolts that only fit
the older 2pc RMS GenI cranks.. They are similar to the stock sized
bolt head. This pic below (for a flexplate, so ignore the part#s) shows
the three bolts. The top is the ARP TQ-conv bolt, to the left is the stock
bolt, then below is the large ARP flywheel bolt for a 2pRMS. (No way
to fit a socket on them when installed)

HTH
mike

 

Awesome pic, makes it all clear to me. I am going to check Summit for 230-7303 and put in an order. Thanks a lot for the help.

 

Kewl.. Just remember they come in sets of 3 bolts for the TQ conv, so you need 2 sets.. More expensive, and you end up with nuts that you don't need.. Shame ARP doesn't just package a set for the application.

 

Ordered! So painless...much better than having to call Parts Dept. of dealer, then drive there after work before they close.

Those bolts are listed as being 7/16-20, and I know when I measure the ones I have they were metric...must be an equivalent size.

Are they the same exact length, Mike?

BTW, what is "UHL?"

 

I just double-checked a set of stock bolts, they are 7/16-20 also.. You might want to triple-check your bolts/crank-threads before running the ARP bolts in.

The ARP's are a 1/4" longer than stock, but I haven't seen any issues with the little extra length on the back side of the crank flange. (U)nder (H)ead (L)ength (UHL) is how long the shank of the bolt is.

 

Just ran out and checked...you're right, 7/16x20. I confused them with another set of bolts I measured the other day.

 

Are the heads on the arp bolts hsorter in length then stock. I think I need .160 so my clutch fits.