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High amp alternator

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Looking for a higher amp alternator for a 77 620 right now I’m running a 35 amp, but my radio and headlights are draining it , looking for suggestions but I want a direct swap one 

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They don't fit very well. The stock alternator diameter is small. A larger alternator needs to be tilted away from the block and will hit the idler arm below it. I used a 60 amp from a t720 but used a Z car lower rad hose fitting to the timing cover. This lifts the lower rad hose and moves it to the rear. I think the 720 alternator mount to the block also lifts it slightly. Even then you had to slip the belt on first then position the bolts it pivots on and tighten. This keeps the alternator as close to the block as possible so you have room to tension it. A longer belt just makes it hit the idler arm.


Try typing ' 90 amp Saturn alternator swap. Ratsun'  on google for multiple posts on how to do this.

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There may be a grease fitting in the top of the later 620 idler arms, mie did. You could grease it and take the fitting out and put in a plug. This would give another 1/8 -1/4"

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I run a 60 amp IR alt listed for L20 720 trucks, in my '73 L16. It is really tight, but doable if you keep fucking with it. The first one I got out of a Pathfinder @ P 'n P, for $25, just to figure out how to lose the voltage regulator, and clean up the wiring looms.


'73, I don't have the radiator core "bump out" that was used in the L20 trucks, but the straight core support. I got a new ABS plastic and Aluminum radiator listed as a replacement for L20 trucks, and was able to mount it so the bottom hose outlet doesn't hit the alt/pulley/fan. Had to take a die grinder to the top of the alternator too, so the adjust arm goes in a notch. hahaha tight little fan belt, but when the junk yard alt died... an easy twenty minute swap for a new $119 one from the auto parts store. So fuggin' broke I didn't want to blow a hundred bucks on a new one... and not be able to jam it in there. Sheeit. But it works great, lights, heater/defroster, stereo, all on at the same time.


I read on one of these alternator swap thread where there is a 65 amp alternator available over the counter, listed for L16 510s... with air conditioning. Same physical size as the 35 amp L16 alts. But I never could find them. 


Why can't a bracket be modified of fabricated to run 110 amp alternator on the drivers side? Seems like a ton of room? Anybody tried it? Got OICS?? 

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