88 Iroc Project

iTrader: (2)

Little confused as to where I need to have the keyway cut into the stock crank hub??
From my hours of reading it seems it is best to have the hub keyed to avoid slipping at high rpm I just don't know where to have it cut. Some say it doesn't matter because the balancer is nuetral and some say top center?
Also, what to do about timing marks, timing tab, balancer. As you can see in picture #1 I received the motor with a 6.75 balancer (not sure what the original owner was intending to do for serpentine). I have a hub and balancer which I purchased from an identical motor which is 7.5 (which looks like it will hit the timing tab). What is the best option for making this work? I don't have the $400 for the ATI balancer. Does someone make a pulley that would bolt to the 6.75 balancer and would line up with the serp setup?
Engine is a 95 LT1 caprice going into my 88 iroc. Will be using the original 305 flywheel. Will be carbureted with hei dist as well.

Any help IS GREATLY APPRECIATED!!!
pic#1


7.5 hub/balancer


Soon to be installed LT1 (hopefully)

chevyowner02

iTrader: (3)

http://www.thunderracing.com/catalog...vid=4&pcid=239

Atilla the Fun

that link really doesn't answer the question. The easiest solution is to get a crank from any '87-up 350 that was NOT an LT1, but then you're also going to be paying for re-balancing. But the LT1's timing cover may prevent you from getting the damper on far enough to line up with the 305 accessories. Your best bet is to either put the LT1 back to it's stock configuration, or sell it and buy a non-LT1.

88 Iroc Project

iTrader: (2)

Thanks!
I did see this already during my research but didn't want to spend $90 when i can get the stock hub keyed for about $25.
I'm broke

FSTFBDY

iTrader: (33)

LT1 cranks have the slot for a key. the HUB doesnt. He just needs to have his HUB/Balancer sloted for the key.

to the OP. let me do some digging. I have a stock hub that was slotted somewhere. I swapped to a billet one when I put the 383 back together and put a Super charger on mine. I think I might have tossed it out since I knew I wouldnt need it.

If I cant find it. any machine shop should be able to do it for you. On your stock one Its gonna be in the location of the pointed nub on the hub and balancer.

I would deff. remove the Stock SBC style balancer because it not gonna line up with anything LT1 accessory wise with a pulley on it.

Been there done that. I was gonna run all my stock 92 accessories on a LT1 but nothing lines up. So I just ended up running all stock LT1 F body stuff. This worked out great for the addition of the novi 2000 sc.

http://www.cecoatings.com/images/Car.../IMAGE_348.jpg

88 Iroc Project

iTrader: (2)

Thanks!
These are the stock LT1 accessories/brackets except for the balancer/hub setup.
Since the LT1 is being converted to carb and hei it was neccessary to install the opti cover plate which has the timing tab on it. I suppose I could cut the tab off to accomodate the stock 7.5 balancer but then what to do about setting timing? I can also have the hub keyed for alot less than buying the aftermarket hub.
I'm sure this issue has been dealt with before but I can't seem to find a good thread with the info i need?? AHHHH!!!
Thanks again!

FSTFBDY

iTrader: (33)

see my above post......

I think you making it a little harder then has to be.

Easy way to do this so you can use your timing tab as is.

TDC the engine.

Bolt the stock LT1 hub and balancer together. See those little nubs/arrowes on the stock pieces.. Line them up on the 0* mark on the timing cover. Now take silver/white sharpe and mark everything that lines up with the key in the crank.

88 Iroc Project

iTrader: (2)

Thanks!! I have a local machine shop that will do it for about $25.

Just need to figure out what to do with the timing tab on the "opti delete" cover plate. I know there must be a thread on here addressing this I just cant find it.

FSTFBDY

iTrader: (33)

Swapping back to the LT1 hub and balancer you shouldnt have to do anything with the tab on the cover. Thats whats its made for. So you can Time a carbed LT1.

since a stock lt1 balancer doesnt have timing marks your gonna have to do a little match and mark the stock balance yourself and mark it. the ATI balancers have marks on them already.

How soon your putting it back on? maybe this weekend I'll get a few minutes to go take pic's of how far out the stock setup sits for you.

88 Iroc Project

iTrader: (2)

Thanks
The only problem is the timing tab is good for the 6.75 balancer in the pic but i dont think this will work for the LT1 7.5 balancer? The stock 7.5 hub/balancer sticks out further as well.
I don't understand why the "opti delete" cover plate was made to accomodate a 6.75 balancer instead of the 7.5? Maybe there is an alternate cover plate for the 7.5. I will have to look around but this is the one that was on the motor when i got it

88 Iroc Project

iTrader: (2)

OK I think I was having a DUH moment (again)
Just held it up to the motor and it looks like the balancer will sit out just far enough to clear the tab. Forgot the lt1 belt will come across the top of the balancer anyway. Not helping that this is my first gen2 lt1 and the guy i bought it from had the wrong frigin balancer on there to begin with
Anyway thanks for the info much appreciated. I am going to get the hub keyed tomorrow and swap these out. Hoping to get the motor in before the weekend.

FSTFBDY

iTrader: (33)

Cool. If ya need anymore info just ask.

I converted my 383lt1 to run a distributor and stock harness/ecm so I can run the $59 code for boost. Instead of spendinng TONS of $ on that dang opti delete cover I just machined my stock cover and welded all the holes shut for the opti N water pump hole.