Serpentine saga

[BUDDY]

What is wrong with these pictures?

A picture of the front of my engine - GMPP 350 crate motor - nothing special

I picture of the back of the brackets to go onto said engine.

Tell me what my problem is.







So a few months ago, a friend of mine was getting rid of his crapped out 96 jimmy with a 4.3 V6 in it & he, knowing me pretty well, asked me if I'd like any of the parts off of it before he had it hauled off. I thought for a second & said, "Well, there are a few things I wouldn't mind, let me get over there." Mind you, this was in the middle of the winter in Buffalo, not exactly nice weather to wrench in.

I decided that the parts I would like the most, with the little amount of time that I was given to pull them with was the serpentine belt system from the front of the engine. I know, as well as a lot of the rest of you, that a 4.3 is just a 6 cylinder small block, so a LOT of the parts will interchange, I just needed to take a couple of measurements to be sure.

So out I go into the 12 degree weather, luckily for me it wasn't snowing, but it was getting dark fast & that means even colder. So hurry up!! Long story short I spent a few hours out there in the dark with a yellow floodlamp & a set of sockets & yanked off the serp setup from this old jimmy to put on my much older blazer.

I was stoked! I had always wanted the serp setup because it is a much more efficient way to run accessories & it meant I only had to carry around 1 spare belt rather than three. Plus, I snagged the AC compressor off of this thing as well, so with a few more EBAY deals I could have the OBA setup I want as well.

Fast forward to today. Get up around 8:30 have some cereal & head out to swap this stuff over on my truck. Got all of the old stuff off in about 2 hours & started to mock up the water pump pulley & crank pulley to make sure this whole idea would work. They lined up perfectly, so now I'm even more jazzed. "This will be my best & cheapest mod to date.", I'm thinking to myself when I notice that the fuel line is in the way of where the passenger side bracket wants to be. No biggie, I'm going to a holley TBI setup later this summer & that requires a different fuel pump anyways, but then to my horror my eyes notice that there is....


ONLY ONE FRICKIN' ACCESSORY HOLE ON THE PASSENGER SIDE HEAD!!!

I cannot believe that I overlooked that. Frankly, I assumed that any SB head manufacturered in the last what, 25 years?, had these holes in them automatically. Upon further investigation, I find that this head does indeed have the three holes I need, on the back of the engine!

So I think I got 2 driver's side heads. What a pain in the ass this is turning into!!

My options -

1) Pull the intake manifold & head off & take it to a machine shop to have the holes drilled & tapped. - PITA #1 likely
2) Ditto - see if there is a machine shop that will trade me my head for their head & some cash - PITA #2 but probably in the budget.
3) Ditto - & head(s) off & take them to a machine shop & have them rebuilt & THEN drilled & tapped. - PITA #3 plus more money
4) Ditto & buy some new higher flowing, bigger valves, etc. etc. - PITA #4 plus a LOT more money
5) Leave the head on there, bust out my Ryobi 1/2" drill, drill the holes myself, & then tap them myself - Biggest PITA, cheapest but also most uncertainty of outcome.

I love to "do-it-myself" but this is more than I was bargaining for. I can do the headswap, (with a lot of cursing & busted knuckles), & I probably will, but if you guys think I should try option number 5 & document it for posterity, (good or bad), that's what I'll do.

Worst case scenario, I have to go buy a new head & get nothing for the old head, but I think I can work this out. Plus, this way I'll get a nice new tap set out of the deal.

Tell me what you think!

Later,
Buddy

 

[Chevy305]

or just go back to the V belt setup

 

[Jason4x4]

IIRC, you might also have a problem with that water pump. The belt setup there is off a vortec motor. They have the coolant bypass going from the intake to the port on the water pump. Your block should have the 3rd hole for the bypass where the water pump bolts up. So i think you will need a different water pump too. I would go buy some vortec heads.

 

[lectric80]

The water pump will need to be changed regardless of how you do the heads. The water pump must be a reverse rotation to work with the serpentine setup. I would say that getting some Vortec heads is a good start, and don't try to drill the existing heads.

 

[4X4HIGH]

Only GM V/8 heads from 1987 and later have 4 bolt holes per head on them for accessories. The heads are the same left or right but the early heads only had 3 holes on one end and 1 hole on the other. Also the water pump MUST be a reverse rotation pump to use the serp belt set up.

 

[nova]

My serp set-up uses a normal water pump on it. It goes in the normal rotation belt wise. I got it of a stock gm truck. from the early 80's, but I don't have a/c or an air pump because I threw them out.

 

[sled_dog]

My serp set-up uses a normal water pump on it. It goes in the normal rotation belt wise. I got it of a stock gm truck. from the early 80's, but I don't have a/c or an air pump because I threw them out.

I have NEVER ever seen a serpentine setup with a normal rotation waterpump. Sure you aren't overheating?

 

[lectric80]

They all have a reverse rotation water pump. The serpentine belt does not ride on the grooves of the belt. This is why reverse is required. Look at the pics at the top of the thread and you will see the pulley is flat for riding on the back of the belt, that is why reverse rotation is required.

 

[4X4HIGH]

You probably have the half serp/half V-belt set-up that came out in the early 80's. This is not considered a serp set-up as we are all talking about. Those do use a standard rotation water pump but the water pump pulley is grooved and not a smooth pulley for the later full serp that came out in IIRC 1989.

 

[BUDDY]

Thanks for the comments guys!!

Just for everbody's clarity, I am using a reverse rotation water pump. It's the one that came off the 4.3L. I was also just planning to loop the tubes that come out of he top of it that you can see. At least temporarily.

I've gotten a few different comments on how to handle this, and the most common is to go ahead mount the bracket up & use the additional braces to hold it in place. The other most common is just go ahead & drill, should be no problem.

I'll keep you guys updated.

Later,
Buddy

 

[4X4HIGH]

If you go drilling the heads i'd be very careful as you will probably hit water in the lower holes, the upper shouldn't be a problem as at that point your into the valve cover portion of the head and only oil is there and easier to control a leak than water under pressure.

 

[BUDDY]

If you go drilling the heads i'd be very careful as you will probably hit water in the lower holes, the upper shouldn't be a problem as at that point your into the valve cover portion of the head and only oil is there and easier to control a leak than water under pressure.

Agreed! That's all the other advice is telling me to do anyways.

Later,
Buddy