jimmyp

iTrader: (1)

Im doing some dyno work with an ls1. The motor came from an auto vehicle. I apparently need a manual bellhousing to connect it to the dyno stand. What are my options?

G-Body

iTrader: (4)

Any bellhousing that will bolt up to a SBC or BBC will bolt up to a LSx, there will be an extra bolt hole in the bellhousing, but you can leave that bolt out without any consequences.

jimmyp

iTrader: (1)

thats what i wanted to hear! thanks
Now I just need to figure out how to adapt the flywheel to the splined shaft of the dyno

Novas Forever

You may want to be sure that the flywheel or flexplate will fit in the bellhousing you choose. The stock LS1 flywheel is as big as the old 163 tooth one from a small block and needs the big bell housing.

VideoMaker

iTrader: (5)

im using a 1967 remanufactured bellhousing 4 11/16th bore allows 14inch flywheel. everything bolts up to the engine except for top bolt. doesnt pose a problem though

jimmyp

iTrader: (1)

Ok so if i go to the junkyard and find an old manual on any sbc I can use the flywheel, bellhousing, and clutch assembly and it should work on the ls1 block

G-Body

iTrader: (4)

The old style GEN I flywheel will not bolt to an LSx motor, the crankshaft bolt pattern is different. I don`t know if the clutch assembly will work either.

jimmyp

iTrader: (1)

so any bellhousing will work but i probably need a gen 3 flywheel/clutch?

G-Body

iTrader: (4)

Yes, any SBC/BBC bellhousing will bolt up, but you need to use a GEN III flywheel. I am not sure about the clutch, I think you can get away with using an old style clutch if you are running an old style transmission, at least that is what it sounded like in a few threads I read, but I am not a manual trans expert.

jimmyp

iTrader: (1)

lol me neither....i couldnt find my way out of a paper bag when it comes to manuals

jeepinpete

An old clutch will bolt up to the Gen III flywheel. I have confirmed with with a '04 GTO flywheel, and a '89 Chevy truck clutch. The only thing you will have to do is pull the two dowel pins out of the Gen III flywheel.

vortectoy

iTrader: (1)

As far as I researched, you have to use a conversion flywheel thats like .400 inches thicker. Or have I been misled? I am going to be mating a 2003 corvette ls1 to an 88 chevy truck sm465. If i dont have to buy the $450 flywheel, that would be sweet. JeepinPete...what spline is your clutch? 10 or 26? I have a centerforce clutch.

jeepinpete

I am using a NV3500 out of an '89 pickup. It uses the same clutch as the SM465. The GM swap guide calls for flywheel pn 12561680 for older trannies. I just haven't been able to figure out what application it is used in so I can find a used on cheaper

To date this is what I have figured out. The SBC flywheel is significantly thicker than the GTO flywheel. The SBC pressure plate is quite a bit thinner than the GTO pressure plate. The SBC clutch disc is also quite a bit thinner than the GTO disc. The pressure plate bolt pattern is identical. Does any of this help, probably not

I am going to try using the SBC clutch with the GTO flywheel. The fingers on the pressure plate will be a lot closer to the engine. This will create geometry issues with the release arm. I intend on getting around this by using a longer throw out bearing. GM has used five different length TOB's over the years. The most common is also the shortest, which is used in my application. So long as the pressure plate is no more than .5" closer to the engine than normal, I should be able to simply use the longer TOB to compensate. For a list, check out here There is a chart towards the bottom of the page...

G-Body

iTrader: (4)

PN 12561680

Chevrolet Cab & Chassis Silverado

2001-2003
6.0L Eng, Gas, Standard Trans
Chevrolet Silverado

2001-2006
1500, V8, 4.8L Eng, ...

2001-2006
2500 HD, 3500, V8, 6 ...

2001-2004
2500, Standard Trans

2001-2002
V8, 4.8L Eng, Standard Trans

2001-2002
V8, 6.0L Eng, Standard Trans
GMC Cab & Chassis Sierra

2001-2003
6.0L Eng, Gas, Standard Trans
GMC Sierra

2001-2004
2500 HD, 3500, V8, 6 ...

2001-2004
2500, Standard Trans

2001-2003
V8, 6.0L Eng, Standard Trans

GMPartsdirect.com >catalog > agree to policy/start catalog > search by PN/select make (chevy) > click on description.

It will not work if you just put the PN in on the first page, but if you go through the catalog you can use it as a cross-reference

jeepinpete

Thanks G-body, I will make use of that...