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SASKCHEYENNE75

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1986 Chev K30 Crew Cab
Originally a 6.2 Diesel swapped to a SBC 350 4 bolt main

Truck has sat for a few years and obviously shares parts with the original 6.2 so making it a bit more confusing. The truck had no alternator when I got it so want to make sure I get the correct one. I posted a pic of the alternator bracket and plug end. There are also 2 red wires that go on the post. I can't find an external voltage regulator so assuming I need to get an internally regulated alternator? Is that the correct plug??
Thanks!
 

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legopnuematic

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Yes that is the correct plug for an internally regulated alternator. Externally regulated alternators use a different style plug.

I believe that an externally regulated alternator and internally regulated are the same as far as mounting is concerned. So the brackets should work for either type. You will need a 10si or 12si alternator for your truck.
 

SASKCHEYENNE75

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Yes that is the correct plug for an internally regulated alternator. Externally regulated alternators use a different style plug.

I believe that an externally regulated alternator and internally regulated are the same as far as mounting is concerned. So the brackets should work for either type. You will need a 10si or 12si alternator for your truck.
Thank you!
 

SASKCHEYENNE75

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Yes that is the correct plug for an internally regulated alternator. Externally regulated alternators use a different style plug.

I believe that an externally regulated alternator and internally regulated are the same as far as mounting is concerned. So the brackets should work for either type. You will need a 10si or 12si alternator for your truck.
I think it was the two red wires that go to the post throwing me off. I thought an internally regulated alternator only had 1 red wire to the post
 

Ricko1966

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Go to the parts store ask for an alternator for 1986 c10 with a 305 automatic,ac and pwr steering. Come home bolt it on problem solved. IDC the engine us from a 1970 Chevelle,IDC you have a 350. I gave you the simplest exact info the parts store is going to ask for. Pick up a piece of steel 3/8ths line while you are there and bend up a decent fuel supply line before you have a fire.
 

SASKCHEYENNE75

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Go to the parts store ask for an alternator for 1986 c10 with a 305 automatic,ac and pwr steering. Come home bolt it on problem solved. IDC the engine us from a 1970 Chevelle,IDC you have a 350. I gave you the simplest exact info the parts store is going to ask for. Pick up a piece of steel 3/8ths line while you are there and bend up a decent fuel supply line before you have a fire.
Thank you....yes I absolutely am getting a steel fuel line. Its on the to-do list!!
 

75gmck25

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The easiest choice for a simple install with original brackets is the 94 amp 12si alternator. It bolts on just like the original (which may have been a 10si).

Alternators have Lester exchange numbers on them to make it easier to figure out which one you have (since the cases are very similar). The Lester number on my 12si is P7294-3, and it has the right clocking (position of the wiring connectors) to replace the old 10si.

You can also disassemble the two halves of a 10si or 12si and rotate the case to change the clocking. You want the two wire terminal to end up on top where it’s easy to see and reach.
 

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