I need to do a valve job on a stock 1997 merc 330. I was looking around for some of the parts I needed and came across a mercruiser 'L29 Exhaust Valve Kit' on ebay. It included 8 new exhaust valves, plus all the top end gaskets. The merc part # for the kit is 814506A1. I bought the kit ($50 + shipping) because I thought it was a good deal just for the marine gaskets. The question I have is that the valves included with the kit are merc part # 803011, while the part # for the valves in my engine is 814506 (same 6 digits in the kit part #). Anyone know if the 803011 and 814506 exhaust valves are interchangable?
Also, while the heads are off, any worthwhile enhancements that can be made 'on the cheap'? This an early gen vi engine, weber carb, all stock...

Is there a specific reason why you did not just get the existing valves ground? I would be hesitant putting any valves into a perf ormance marine engine that do not say manley severe or extreme duty on them. I've dropped way too many valve heads due to suspect valve selection. Even new valves should be trued in a grinder to ensure concentricity with the stem, so if your old valves are servicable your best bet in my opinion is to get them ground since the new should be ground anyway. Make sure the guy that does the grinding puts in generous seat areas for disipating heat. Check and re-set valve spring seat pressures and rates. Hopefully the head gaskets are a good quality fel pro. Sorry, I don't have any useful info on the specific part numbers you mentioned. Good luck.

BT