4.3 v6 serp setup

[72tutone]

Just got back from the yd this weekend and I yanked serp brackets and pulleys etc.
I've read on the board that its possible the v6 crank pulley might not work on my SBC. Might require a v8 creank pulley? Can anyone confirm this?

[hugger6933]

No I think the pulley is the same. I know I've taken the 4.3 set ups and put on small blocks before. I am pretty sure the bottom pulley will work for you

[72tutone]

Sweet. That's what I need to know

['68 Newtricks]

Yep, swapped a '92 1500 V6 serp set up onto my blazer's '79 400sb with TBI heads.

that's all I know

[72tutone]

Hmm after more investigation I seem to be running into an issue

I know some say the depth is the issue on the 4.3 pulley but mine seems to be fitting the snout into the stock 8" harmonic balancer. The crank pulley snout seems to big?

Has anyone seen this before?

[hugger6933]

How much too big is it? Can you start all three of the outside bolts? if so start them then run them down then put the crank bolt in and don't think of it again. Most of you pressure [or whatever] is gonna be on the three outside bolts. Jim

[72tutone]

Yes, it can fit the 3 bolts. The snout just seems a tad bit too big.
I googled the part numb 10085754 and it seems to fit a variety of chevys from 95 and onward 5.7 and 4.3 motors.
Are the 5.7 vortec motors not running an 8" balancer? The smaller 4.3 probably run one smaller but I cant imagine everything is hinging on the balancer to be the problem.

[72tutone]

Originally Posted by 72tutone

Yes, it can fit the 3 bolts. The snout just seems a tad bit too big.
I googled the part numb 10085754 and it seems to fit a variety of chevys from 95 and onward 5.7 and 4.3 motors.
Are the 5.7 vortec motors not running an 8" balancer? The smaller 4.3 probably run one smaller but I cant imagine everything is hinging on the balancer to be the problem.

I wrenched in the bolts and it removed brief metal around the snout of the pulley. I can snug it now down to the balancer itself.
I would think this would be ok.

[hugger6933]

It sounds like a bur or something to me if you can tighten the bolts down and it pulls the pulley up it will be fine. You will love the change that set up brings in looks under hood. Jim

[mechanicalman]

Originally Posted by 72tutone

Hmm after more investigation I seem to be running into an issue

I know some say the depth is the issue on the 4.3 pulley but mine seems to be fitting the snout into the stock 8" harmonic balancer. The crank pulley snout seems to big?

Has anyone seen this before?

You need to place that pulley onto the balancer and see if the part that fits into the balancer is tight or if it moves too much. That part needs to be centered and the three bolts are not enough to do that, it has a hub for a reason.

I've read that the balancer is thicker on the V8 and you have to use a V8 pulley anyway.

"had to get a V8 specific crankshaft pulley as the V8 uses a different thickness harmonic balancer and consequently different pulley". See post #6.
http://67-72chevytrucks.com/vboard/s...d.php?t=525910

[72tutone]

Whats really strange is the part number stamped on this pulley which is a GM pulley OEM shows that it fits vortec 5.7L 1500 trucks as well as 4.3 motors as well. Part number 10085754
"This product fits 570 vehicle variants.
Cadillac: 1 models, 67 variants between 2007 and 2013.
Chevrolet: 16 models, 322 variants between 1987 and 2013.
GMC: 8 models, 181 variants between 1991 and 2014"

This is why I'm scratching my head.

[mechanicalman]

Originally Posted by 72tutone

Whats really strange is the part number stamped on this pulley which is a GM pulley OEM shows that it fits vortec 5.7L 1500 trucks as well as 4.3 motors as well. Part number 10085754
"This product fits 570 vehicle variants.
Cadillac: 1 models, 67 variants between 2007 and 2013.
Chevrolet: 16 models, 322 variants between 1987 and 2013.
GMC: 8 models, 181 variants between 1991 and 2014"

This is why I'm scratching my head.

Quote from post #5:"I know some say the depth is the issue on the 4.3 pulley but mine seems to be fitting the snout into the stock 8" harmonic balancer. The crank pulley snout seems to big"?

Quote from post #10:"You need to place that pulley onto the balancer and see if the part that fits into the balancer is tight or if it moves too much".

Did you do that? If the snout fits, then install it and see if the depth is right. If the snout don't fit, then it don't fit nothing to discuss.

Anything else? Diameter or belt width?

[WIDESIDE72]

Is the balancer being used the original 6-3/4" from the swp set up or an 8" from a later model lwp set up? I am going to be doing a similar swap soon but since the truck didn't have an engine I am using all of the serpentine parts (brackets pulleys balancer, etc) scored it locally on craigslist already removed. Guy we the engine in his s10 blazer and had bough another engine. Didn't have room for spares. I got all the brackets, braces, pulleys, bolts, two fans two used water pumps (can't figure that one out), power steering pump alternator and an Ac delete pulley for $75. Not to mention the half days time it takes to remove it!

[72tutone]

This is using the original 8" nodular balancer that was in my 72.