You should have a Thunderbolt IV on your 92, and it does not have a rev limiter. Lots of boats work real well with the stock setup, but some guys change out to MSD or others because there is not much tunability with the stock setup. If you want to sell your module, let me know, I could use one for a 502.
Also, most all big blocks with thru-hull exhaust get that black soot on the back to some degree, even fuel injected ones. If you want to tune the Weber carb, it is the same as an Edelbrock Performer and as such you can use all the Performer jets and rods.