thank you captian obvious, lol. But any roller set cloyes sells is based on a 2nd generation lt1 which has the vented optispark, for the first generation a roller timing set is not available, unless i'm missing something. actually both the roller timing sets i'm seeing are double rollers, theres a 9-3157, and a 9-3151 and the difference being the 9-3151 has a iron sprocket.

 

to come to think of it, when searching on summit, you search for a "LT-based" engine which gives you results for a lt1 and a lt4 since parts are interchangable.

 

Check a 9-3151.
I have one in my hand and it is a roller and the sprocket's appear the same(no iron). ya can get it with an oversized crank sprocket(std SBC) or get the GM spect one which has a loose chain that take load off of the front cam brg. It.s got enough load driving the pump.

 

oh.. nevermind I guess the 9-3151 isn't a double roller, summit just messed up and put it as one on the description... but none the less The 9-3151 is for a 2nd generation LT1 just like the 9-3157 meaning replacing the optispark, cover, etc, etc, just like with the 9-3157 double roller. I beleive reason the 9-3151 is more expensive is because it uses a iron sprocket unlike the 9-3157 which uses a billet steel.

 

note from the 3151:
"Timing chain has a 1/2 in. pitch. Can be installed on Generation 1 LT1, if the OptiSpark is updated to the new, second design. This will require new ignition, new front cover, and cam change to second design cam, the nose is different. The older OptiSpark"

 

does the 9-3151 have the hole to run the 93-94 non-vented optispark distributor??

 

I knew they made one but mine is for '95 up Sooooo.
And it does have billett for both sprocket's.

Time to upgrade.

 

the reason my std SBC cloyes double roller didn't work is because I couldn't run the my non-vented opti off of it...

 

hmm... If I could find the cloyes roller timing set like the 9-3151 for a 93 (non-vented opti) i'll prolly buy it. can't seem to find that though. I actually called summit the other day and the only thing they could find me was that 9-9100

 

It has a hole in it for the dowell pin along with three bolt holes. It also has a 1/2-9/16 hole in the center.
Call Cloyes.

 

I believe that is the same as the 9-3145 SBC double roller I had

 

Doesn't your opti drive off of a splined shaft in the middle of the cam?

 

yeah, just got off the phone with cloyes, unfortunetly the only timing set they make for a splined non vented opti spark is the 9-9100 which isn't a roller and the sales guy at cloyes actually just reccommended just using the stock timing set and chain if i'm not prepared to spend $400 to replace the distributor, front cover, etc

 

yes.

 

i suppose the best time to replace that non vented opti spark to a vented one might be when the mine goes out down the road (from what I hear, they are pretty ****ty) and then just move up to a double roller.