I have a 1991 Chevy pickup with a blown up small block that came with factory A/C. I managed to find a nice motor home 454 engine for a little more torque but it uses a funky aftermarket A/C compressor mounted to the factory accessory drive with a combination of serpentine and V-belts that I don’t want to use. I’d like to add A/C to my existing big block accessory drive but none of the local junkyards carry big block Chevy engine parts so the A/C brackets seems to be pretty scarce. I could go with a full aftermarket accessory drive but that will cost much more than I paid for the engine. Is there another way to go?

B. K.

I think we have a really good recommendation for you. Our friends at Kwik Performance offer a very simple conversion kit that works really well and is very affordable. The key to their conversion is using a factory small block Chevy serpentine belt accessory drive that was stock on late 1980s and early 1990s small blocks in trucks along with 90 degree 4.3L V6 engine found in the first generation S-10 pickups and Blazers.

It just so happens that this is the exact accessory drive you have on your 1991 small block pickup. The Kwik Performance kit uses the entire small block serpentine accessory drive brackets on both sides that mount the alternator and power steering pump on the driver side and the A/C compressor on the passenger side. These brackets are re-used along with the small-block serpentine crank pulley. The Kwik kit merely adds adapter brackets to mount the small-block brackets in the correct locations to align with the crank pulley.

The Kwik aluminum adapter brackets bolt to the big block cylinder head and block to accurately position the small block accessory drive on a big block. The Kwik system also includes a spacer that bolts to the harmonic balancer to allow the use of a stock small block serpentine crank pulley. This will also require a reverse rotation Chevy big block water pump. (Image/Jeff Smith)

We’ve actually tried one of these systems on a big block and it all bolted up just like Kwik Performance intends, so we’d say this is the least expensive and best solution for your application. The part number is K10473. Our sources also tell us that you will also have to trim the factory plastic fan shroud slightly in several places because the brackets have moved everything forward.

To bump this information further along, we referenced that this accessory drive could be found on 4.3L 90 degree V6 Chevy and GMC Blazers and S-10/15 trucks. That’s because that engine is essentially a V6 version of a small-block Chevy. So this accessory drive can also be used to bolt on to any small block Chevy to update a V-belt system. These systems are becoming more difficult to find now because they are 30 years old. But those engines and parts are still around in junkyards and abandoned trucks and they make for a great upgrade to serpentine for early V-belt style small block Chevys.

This is a photo of a Kwik Performance kit installed on a 454 Chevy big block. (Image/Jeff Smith)
Keywords
A/C, Ask Away, belts, engine accessory drive, Jeff Smith
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Author: Jeff Smith

Jeff Smith has had a passion for cars since he began working at his grandfather's gas station at the age 10. After graduating from Iowa State University with a journalism degree in 1978, he combined his two passions: cars and writing. Smith began writing for Car Craft magazine in 1979 and became editor in 1984. In 1987, he assumed the role of editor for Hot Rod magazine before returning to his first love of writing technical stories. Since 2003, Jeff has held various positions at Car Craft (including editor), has written books on small block Chevy performance, and even cultivated an impressive collection of 1965 and 1966 Chevelles. Now he serves as a regular contributor to OnAllCylinders.