Serpentine belt conversion?

[1986Silverado]

Anyone ever did it on a pre serpentine truck? Also what is required? Reason I ask is because I have the opportunity to get all the accessories and brackets off of a 92 Chevy Astro van with a 4.3 for FREE, could basically get the whole complete engine, which is blown. Would that work on my 86 and what would interchange as far as parts already on my truck? Anybody have pics?

[corn]

Dont forget to get a serpentine waterpump. The impeller runs in the opposite direction...corn

[ElGracho]

I just did this on my 84. It should be the same parts as that astro van. You will need to get a pulley to replace the air pump (or use the air pump) I used the one that normally comes with the GM Performance Parts serpentine kit. On these trucks it moves the alternator and air conditioning compressor to the opposite sides. Just like cornfed said, you need to use the later waterpump designed for reverse rotation.

Here's a pic of the front of my engine:

[1986Silverado]

My real question would be will the brackets bolt to my 86 heads and block? Also would I just need to replace the pulleys on my accessories and get the reverse flow water pump or will I need to get all new accessories?

[SanitysBane]

you probally will need all new accessories, none of the stuff would bolt onto the serpetine belt setup, i've done this but it was 454 to 454, so i have no clue if your stuff will bolt up.

[ElGracho]

I would search for a setup that came off of a running car that has all the accessories. This would be a pretty expensive swap if you have to buy everything new. As far as reusing the old stuff, the alt is different, the PS pump has a different reservoir (the metal can around the outside), the A/C compressor has the serpentine pulley and clutch. The brackets will bolt to your engine except for possibly one bolt into the heads. You can leave that one out according to GM Performance Parts.

I found my setup on Ebay. Heavy to ship, but I still got it for less than the cost of a new alternator, and the one I got had a new alternator!

[1986Silverado]

Well went and looked at the setup today and it is different than yours ElGracho.............the alternator is where your a/c compressor is and the a/c compressor is where your alt. is Also below the alternator on yours looks like the smog pump, on the setup I'm looking at is the power steering pump. Does not look as if it has a smog pump. It is a complete setup, and the vehicle it is on was running till the engine blew about 6 months ago.

[ElGracho]

Sounds like it could work. If it was on a 4.3, it should fit on a small block no problem.

Do you have any pics?

Also, below the alternator on mine is the P/S pump. The other side is where the smog pump would go, but I have the smog pump delete pulley there instead.

[SanitysBane]

i didn't use a smog pully or anything there, just had to get a shorter belt and have more wrap on the crank pully

[gldevall]

If it's free go ahead and get it. If it doesn't work, sell it.

[1986Silverado]

Originally Posted by gldevall

If it's free go ahead and get it. If it doesn't work, sell it.

Well it is free as in no cash changing hands, just gotta pull the tranny out.

[kwmech]

Originally Posted by cornfed63

Dont forget to get a serpentine waterpump. The impeller runs in the opposite direction...corn

And the fan--- and the fan clutch

[DirtyLarry]

Yes, do it…..serpentine is the way to go. I have been through this swap a couple of times. The serpentine system looks cleaner, works better, makes a neat whistle noise and I swear, I even feel like I even have more power.

Yes, you will need a later model alternator (and rewire it to an internal regulator for the Pre-1975 trucks, which is a good thing.....63 amp vs 105 +). The good news is you can use your original power steering pump but will need to swap on a serpentine belt type pulley, you will also need an R4 A/C compressor or the A/C delete pulley and the common stuff that has been mentioned above such as reverse rotation waterpump, clutch and fan. If you do this swap do not bolt the brackets to the engine and heads as studs and nuts are much more ridged and the original fastening method.

There are a few options for donor engines to pirate serpentine belt goods from to swap onto any small block:

1987 through 1992 4.3L V6, 5.0, 5.7L V-8’s brackets from any C/K truck, G-van, azzhole van, P-chassis etc. - These brackets are ok but the brackets are all made of an one piece stamped steel concoction and are subject to cracking at the main engine bracket. Avoid this setup.

The other option and most common, is to use the brackets from the 1993-1995 small block or 4.3 V-6 as the brackets are made of a 2 piece cast aluminum setup. GM Performance Parts even sells these in kit form. The first picture below are these type brackes on my old small block.

Or….you can use the brackets that ElGracho used on his 84”. These are from an F-Body or B-body car that came on both, the L05 and LT1 small block.

Lastly, brackets from a 1996 through end of production of 4.3’s and 5.7’s will work as well but a different alternator will be needed.

One word of caution, if you add serpentine brackets to a pre-1997 small block you will need to drill a hole on the passenger’s side head. I had to do this to my 1978 K10 when I still had a small block and added serpentine to it. Believe me, it is scary drilling a hole in a perfectly good cylinder head.

In May 2003, I ditched my small block for a 454 HO. I used 1999 model year L29 454 serpentine brackets and accessories. Picture below.

[784X4GUY]

DirtyLarry...I was just wondering why did you have to drill into the passenger side head. After you drilled it what did you do, tap the hole? Is there a bolt that's apost to go in there? Thanks Mike

[cliffsta]

Personally i wouldn't go to serpentine, cause then you got the probelm of all new cars...when 1 thing goes, your stuck, cause everything is on that belt.