How to use a Small Block Chevy Serpentine drive on a Big Block Chevy
This install was done on my 1980 Chevrolet Malibu
My car currently has no Engine because I'm putting a new one in it :-) A "working on it" engine picture is below along with a "as it sits now" picture of the car. This install was done on the previous '71 LS-5 454. New engine is a 0.030" over 1/4" stroker which equals a 489 cid.
(warning large picture LOL)
Before you start you'll need a few things, Including a '88-'92 F-body Serpentine drive setup, one 1/2" x 4" x 12" piece and one 1/4" x 4" x 12"piece of Aluminum, a reverse rotation Big Block Chevy waterpump (for '88 and later BBC powered C/K trucks without v-belts, you will also need a crank pulley for the same application because the Small Block one will not line up correctly, all the other F-body pulleys were used. A bench vise is a necessity along with a good drill/drill press, Sawz-All or jigsaw and plenty of patience
Off with the old
Rip, Tear, whatever floats your boat.......just cleaning the front of the engine off :-)
New reverse rotation aluminum waterpump by Edelbrock is the starting point of the install, but a standard iron one from a Big Block truck with serpentine will work
I installed the new aluminum waterpump and the pulley to serve as a baseline guide for the rest of the pulleys because it's the one that can't be changed very easy. Next I put the A/C compressor, Alternator, and power steering pump into their respective brackets and putting a long bolt through both brackets outer holes (you may need to make the hole in bracket larger to fit the older BBC's 7/16" bolts) to the outer most accessory hole in the heads (see below)
with the outer bolt holding the bracket up I then lined the pulleys up and measured the amount of space between the head and the accessory brackets......The drivers side needed a 1/2" spacer and the passengers side I used a 1/4" plate to keep from drilling and tapping the cast iron head. I had a pretty good size piece of 1/4" aluminum plate and had originally thought of stacking two pieces for the drivers side but lucked into a nice chunk of 1/2" x 4" aluminum bar about a foot long in the scrap pile at the local recycler....Perfect!! the spacer brackets needed to be just a shade under 4" to reach all of the bolt holes in the BBC heads. I made some cardboard templates which I transferred over to my aluminum pieces. I cut the basic shape of the 1/4" and the 1/2" mounting plates using a Sawz-All and a pretty coarse metal blade (12 or 14 teeth per inch I think) I didn't get any pictures while I was making the plates (Oops) but here are a few of the finished items....you'll get the idea. Also notice the large holes in the upper brackets. These are for the cooling/casting screw-in plugs in the factory iron heads.....my new aluminum heads don't have these so you might not need them if you're not using factory GM heads
The picture directly above is a side view of the passenger side lower bracket. In order to clear part of the SBC pass. side bracket I had to trim this piece from 1/2" to 1/4". it wasn't hard to do using the Sawz-All and a bench vise, Just clamp the piece in the vise the wide way with 1/4" above the surface of the vise. Now make the 1/4" deep cut using the vise as a stop, then cut it length ways using the vise as a guide so it stays 1/4". I also used Heli-Coil's in all of the bolt holes that only threaded into the aluminum plates, for strength.
Here are the plates bolted to the heads. The driver side SBC serpentine bracket actually uses all of the original attachment holes, Where as the Passenger side I could only manage 4 out of 5 of the factory holes
The driver side SBC bracket fits the new plates with few other modifications besides enlarging the holes so that the 7/16" bolts will fit through it
The passenger side on the other hand took a little more persuasion :-) here's the uncut bracket
Here's the bracket after a little work to the lower end. The second Picture is of the backside, in it you can see why I had to cut the lower mounting plate down to 1/4" thick at the top, and I also had to do a little grinding on the bracket itself
The backside of the bracket required attention also. Since I didn't want to drill and tap into the cast iron heads for the bolt holes that didn't line up with the bracket I had to take a 1/4" of material off of the back of the bracket (not as bad as it sounds) the unmodified bracket is shown in the first picture and the shortened legs of the bracket are shown in the second
I was getting closer to the end of my little project. Most of what was left was finding or making the right length bolts to fit the brackets and not contact the heads. but compared to the head scratching good time I had making the brackets it was a breeze ;-) Here are a few pictures of the bare brackets mounted to the plates (sorry about the blurriness in some of the pictures)
The last few things to do were mount all the accessories into the brackets run the wires for the alternator and measure for a serpentine belt. Mine ended up being a 100" 6 rib belt but if you take on this project it might not end up the same :-) You can either find a Camaro/Firebird with serp. setup A/C high pressure hose and see if it will work or I'm sure a good A/C shop that can make hoses will be able to fabricate some for you.
Here are a few pictures of the assembly installed
Here's one last (large) picture of the serpentine setup so you can get a closer look if needed
Any questions you can email me at firstname.lastname@example.org