1100833 & 1100881 alternators

[Greg L.]

What's the difference between these two 1969 42A alternators and are they fully interchangeable?

Thanks

Greg Linton
#45455

[Jack H.]

Re: 1100833 & 1100881 alternators

Typically, when two alternators have similar PN's and share the same output current rating, the difference lies in two places:

(1) Clocking: the position of the rear case half relative to the front case half when they were bolted together by Delco.

(2) Pulley: the size, depth & physical offset of the pulley that's installed, whether it has a discrete or integral fan, or whether it originally shipped from Delco without a fan/pulley.

[Greg L.]

Re: 1100833 & 1100881 alternators

Thanks Jack. The reason I ask is because they are both listed as 69 390 and 400 hp alternators in the TIM&JG but I have never seen a 1100881 for sale anywhere...just the 1100833 number.

[Mark #28455]

Re: 1100833 & 1100881 alternators

There may have been a change in the internals. Look at the 825, 882 and 884 alternators for the higher amp cars. In the service manual (printed at the start of the model year) it only listed the 825 alternator, yet it appears they were phased in through the year. My L88 (#62xx) had the 825, My L89 (#17xxx) had the 882 - both were engines without power brakes or power steering and used the same pulley and clocking.
Mark

[Mark #28455]

Duh! L88 HAD power brakes! *NM*