What all will I be changing when putting the HEI on it? Can't say that I have a lot of ignition experience.
The quadrajet was actually just a loaner, when I first got the boat out. So I ordered the 750 when I gave the carb back.
Also, I have two impellers hanging on the wall. Will they be marked, as to if they are A, B, etc..?
Your used impellers should be stampoed as to cut and assuming the have not been cut (and not restamped) the letter designation should be accurate ....depending on the "build" of the engine a B impeller would not be a great choice for the 455, better to use the A or even a AA to keep the WOT rpms to a lower number due mainly to the inherent oiling issues common to the Old motor The 750 Holley is a good choice for the Olds , To change to HEI you'll have different plug gaps and delete your current ignition coil , a couple very minor wiring changes Happy to help if you have questions or need Tech help Tom
If you want your 455 Olds motor to live,It needs oil restrictors in the block under the main bearings,a Hi Volume oil pump and a 10 to 14 Quart oil pan .All this was developed by Joe Mondello (RIP) years ago
I switched over to a stock HEI some years ago when I rebuilt my 455 and absolutely love it! Love the fact I can get cap and rotor at any autoparts store and it makes my motor run way better than the dialed in points I had previous! I also run a 750 carb, I currently have a demon on mine but might be switching back to my edelbrock 750 since I use the boat for waterskiing and wakeboarding and it runs perfect with it for some reason.
I believe the impeller I have, that has been sitting on the shelf for 30 years, is an A trim. It is not stamped on it, but the part number L 2507 is. And from what I could tell that is a Berkeley A part number. Wish I knew what was in it, but I am sure it is smaller.
The intake side of the impeller looks really good, sharp edges and no pits. However, the other side has a good bit of pitting and rough edges. Which side is more critial, or are they both highly important to keep smooth?
I looked up the schematics on Berkely for pulling the impeller out, but really how big of job is it? Do I need to have a rebuild kit handy before doing this? Guessing I should not tackle it if I want the boat out for Memorial Day weekend?