Well, the same thing happened to me! A few years back, I was having trouble with the original 28 year old one and could not find an OE one fast so I got one from CDI electronics which worked just like the original. I ordered the OE one just in case this didn't work right. It came in a box (BRP part) marked 987740 but on the module itself, it says the same part number as you have 763786. I called the people I ordered it from (Crowley Marine) and they thought it was the right part. Well I could not send it back by the time I noticed the discrepancy but if its really for the electronic distributor, then I'm kinda glad I kept it because then I could use a Delco EST when I repower the boat with new 4.3 Vortec. Do you know for sure that this is not for a points distributor?