I went the morphodite bastard motor route. I bought a donor boat with a rebuilt 4.3L in it. The previous owner took a '93 block and stuck a wrecking yard set of Vortec heads on it (marked S-10). The engine was then parked in the boat without anything over the carb except a tarp - no flame arrestor, no nuthin. So hole #6 filled up with water and pitted it bad enough that I bored it again and replaced brand new .020 pistons and rings with .040 pistons and rings. As purchased by me the original 4barrel Rochester carb was sitting on an after market Performa intake with a square bore to spread bore adapter. When I dropped this newly again rebuilt motor in my older boat the carb was an inch too high for the doghouse, so I bought an Edelbrock 1409 square bore Marine carb for it and the calibration kit made for the 4.3L. This got rid of the adapter plate and lowered overall height by an inch. Said factory Edelbrock 4.3L calibration kit was 'waste of money too lean' in a Vortec motor and SummitRacing, believe it or not, refunded the cost of it since I had to recalibrate it all the way up to basically what they put on 5.0L engines. That's the long version.
Short version:
I have a 4 barrel Edelbrock carb, which is the same as the OEM Weber carb, and I had to richen it in primary jets, secondaries and metering rods to work with a Vortec converted '93 motor.
My motor has the steel pan, one piece main seal, the Vortec roller cam, lifters and pushrods, Vortec heads, Performa intake, 1409 carb and Airtex E11003 electric fuel pump. I figure I am somewhere around 240 HP since this configuration would be 230 HP with a balance shaft and just turning a balance shaft costs about 15HP.