Thread: Serpintine system system for early 70`s chevy 350

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I wanted to install a serpentine belt system on my 1974 chevy 350 but I have been hearing that I need an additional hole on the passenger side below the water pump mounting holes to make this work. I do not have this hole on the block. I was going to use a system off a early 90`s gmc 1500 series truck. I really do not want to buy another block just to do this project. What are my options? Any ideas?

Thank you
farmerdick

What accessories are you using? Modern a/c? and alternator? all the chev blocks have 2 holes just above the pan on each side and early ones have one that goes thru to the fuel pump push rod cavity-----
Powermaster has many mounts for altternators that would let you use serpintine belt-but IF you are looking for a system that mounts all your accessories like on newer vehicles-------------

Jerry, I will have a Mustang II rack and pinion, no p/s, will have modern A/C and modern alternator. Will be using short water pump. It will have manual fuel pump delete plate (using electric fuel pump) if this makes any difference. Thanks

Originally Posted by Farmerdick

Jerry, I will have a Mustang II rack and pinion, no p/s, will have modern A/C and modern alternator. Will be using short water pump. It will have manual fuel pump delete plate (using electric fuel pump) if this makes any difference. Thanks

But to clarify, you're wanting to use a salvaged OEM package as opposed to aftermarket parts if I understand your first post above?

Yes, that`s correct. The chrome and billet systems are very pricey. I do not mind using the painted black ones. I can get the OEM used parts for a hundred bucks and recondition them. If this doesn`t work I`ll stick with the v-belt system. This motor will be in a 1941 Special Deluxe Coupe. Thank you.

I did a stock GM upgrade to my 85 Chevy truck......using a serpentine from a Vortec (96 to 2001) truck belt system. Some things that I found were:
1. Of course, the alternator, A/C compressor, PS pump and AIR pump are different than the old V belt stuff. The belt tension is controlled by the idler "pulley" instead of moving the alternator.
2. I cut the long bracket to eliminate the AIR system which I didn't need.
3. The serpentine water pump rotates the opposite direction from the V belt pump.
4. The FAN blades must match the water pump direction.....otherwise, you have a real mystery problem since the air flows backwards and comes out the radiator if you use a V belt fan blade.
5. Your heads may not have the correct hole locations for your brackets
6. There are no different holes for the block, I used a 1980ish block with no problems.
7. System results in a MUCH quieter engine even when using a thermostatic fan.
Would I recommend it? Certainly. The change isn't cheap but a lot of the aftermarket stuff is authentic crap.

Thank you for the additional info. I suppose I could have the machine shop drill any additional holes if needed. I agree with the quietness you get and I believe there is a HP gain with the serpentine system.
Thanks Robot and Jerry for your help. I will be posting photos of this street rod progress in the future.

The first thing you need to do is to acquire the brackets or at least touch one and make a pattern of the three bolt layout that attaches to the head. Then, compare the bracket pattern to your head pattern....as I remember, one or two bolts didn't match. For the attachment to the water pump, I remember using a stud in place of one of the water pump bolts.

Look at the pictures and advice from an old Hot Rod article.
Simple enough.
Serpentine Belt Drive - Build Your Own Budget Accesory Drive System - Car Craft Magazine

I have that Hot Rod article already in my favorites. I tried emailing them but never got a response. I guess I will need to get to the salvage yard and remove that system off the 1500 gmc and take some measurements. Much appreciated info you guts have given me. Thank you.

That is a great article.