AFAIK, the CS130 never was available on the G-body Cutlass. Not even as an option. Every 88 Cutlass RWD came with a 307 V8 and used the fixed bracketry that was designed for the 12SI. I've looked through all my GM literature covering 1988 and no G-body ever mentioned the availability of a CS130 alternator.
My suspicion is that the Canadian Tire computer garbled up and merged the 1988 FWD Cutlass in with the G-body offerings as the FWD Cutlass did come with CS130 alternators. If I were a bettin' man, that's where I'd put my money.
Again, if your wiring system is in good shape, your battery is in good condition, and the alternator is working properly, I see no reason the factory alternator won't keep your stock system happy. Look at it this way, if you are only going to draw 70A max on your system, a 78A will keep up with it. Having a 160A alternator will put out that same 70A, but that's it. If the alternator keeps up with demand, you really don't need any further output.
Stock pulleys puts you around a 2.8 ratio. Generally, Delco alternators were designed for 18,000 rpm (generator speed). That means at 6400+ crankshaft rpm, you run the risk of killing it. How often do you run your street car in that range?
Again, if you're above 13.5 V at idle, you're good. If your system is in crappy shape, you may not get there. For a stock system, that's spending a good chunk of change for minimal gains. But hey, it's your money. I can tell you one thing, on my G-bodies I've never ran anything other than the stock alternators on the stock systems, and I've only had one (rotor ground) go bad on me. I've never needed to "upgrade". If I was going to put a lot of power drainers in the system, I'd run bigger wires, and likely upgrade the entire charging system as well. Probably do a CS144 at that point.
Smaller pulley may do what you want it to do. Stock is around 2.62", the one or two Summit sells is like 2.342" on the alternator. SBC typically use 6.75 or 7" crank pulleys. So...doing the math....puts you around 2.6 multiple for alternator RPM with the stock pulley, but just about 2.9 on using the smaller pulley. So if you're 800 rpm at the crank at idle, You're turning a hair over 2,000 at the alternator anyway. More than enough to start sending some juice through the system. At 2.9 factor, you'd be turning roughly 2,320 rpm. About 12% faster at the alternator. And you STILL likely wouldn't break it as you'd have to turn 6,200 rpm to overspin the alternator.
The chart below says your 63A alternator should pump out about 23A at 1600 alternator rpm. Note the 72A doesn't even start yet. But at 800 crank rpm idle, with a smaller pulley, you'd be @2,320 alternator rpm, which should net you closer to 30A from the chart.
And the 12SI at that same 2,320 alternator rpm gets you almost to 50A. Over 10A better than the stock pulley at 800 crank rpm idle.
Here's a smaller pulley. Fits on 10SI or 12SI. If you're wanting to put a little umph to get some more juice at idle, do this one. Nobody will be the wiser. $16 and an impact gun and 15/16" impact socket. When going back on, torque the nut to 40-60 lbs-ft.
Free Shipping - Powermaster V-Belt Alternator Pulleys with qualifying orders of $109. Shop Alternator Pulleys at Summit Racing.
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