Thunderbolt, or Delco distributor?
 

My parts guy ordered me a distributor cap and rotor for my boat, and the packaging says 808483Q1 rotor and cap kit - Fits all 1997 and older V8 engines with Delco ignitions. My service manual (#16) only covers Thunderbolt IV and V ignitions for 454s of my vintage (1996).

How do I know what I have? Here's a couple pics of mine.... the new one in the package does look very similar (and different from the Thunderbolt caps in my manual which have a vent on the side, etc. ) except the new one's black.

But I'm curious why my manual would ONLY reference Thunderbolt ignitions. In the pictures in the manual, the Thunderbolt appears to have four captive screws in the diagrams. My boat only has two, as does the new one in the package. Picture 3 shows the Thunderbolt type.

http://i28.photobucket.com/albums/c2...eboy/Dist2.jpg

http://i28.photobucket.com/albums/c2...eboy/Dist1.jpg

http://i28.photobucket.com/albums/c2...derboltcap.jpg

Does the one the parts guy gave you look the same as the one on the boat? If so I would think it would be correct. All the ones I have seen are thunder bolts.

It does look similar, except the new one is black. Perhaps the previous owner changed it out for a Sierra, etc.

I won't know for sure until I remove the old cap, but didn't want to do that until I'm pretty sure I have the correct new one in hand.

Figured while I've got the hatch off, I'll do this stuff, as I hate lifting that bloody thing.... :)