For What Its Worth

A good 10si style alternator mount for a Chevy II

I kept having trouble with various mounts for the alternator. They would wobble or bend over time. I also wanted a 100 amp alternator for the fans and all the newer stuff I plan on installing one day.  I had a 12si style 95 amp mounted but the mount was bending and it started dropping belts.   I needed a good mount, for a Chevy II.  Problem is most SBC lower mounts are too low and run into the cross member.  Most are also designed for the 10si style alternator.   Since I have my Rack and Pinion bolted to it, lowering the cross member is not a good idea.   

I bought and installed the
Modern Performance Classics ChevyII lower alternator mount.   It is for a 10si style alternators.  Works great.  There is adjustment, but not a lot.  The right belt for me was 42".  I think I have stock size pulleys.  I had to loosen the water pump pulley to get the belt on.  Then it adjusts well.  It took about 1/2 to 2/3 of the adjustment travel. 

For the alternator I was in a hurry to get the car running for Memorial Day weekend and try to hold to a budget.  There are a lot of after market ones, pricey and often overrated.  I remember an old business close by.  Hammond Bros in Garland TX.   I went in and asked if they had a 100 amp 10si alternator.  He said come back in an hour.  I did and it was ready.  Stock style, but for $71 including core, it was a great deal I thought..  He said it tested to a 120 amps.   I know a lot of people that use their rebuilds and they have done well.

He would not build a 140 amp one, why?  He didn't say, but I think getting 140 amps out of a 10si style alternator is pushing it.  I wouldn't count on their useful life being long at that output.   Too much heat and not a big enough body to dissipate the heat is my opinion.

Digital cameras are great, this was taken with the engine running

Alternator mount

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