using an quadrajet from a 5.7L to trouble shoot one on a 7.4L

[mr300z87]

There is a new freind i recently met at my marina he and his girlfriend just bought a 1974 30 ft Trojan which has a single Gen 5 or 6 7.4L with Q-Jet. Before buying the boat as a summer get away it had not really been run in a number of years. The engine runs smooth but has cold start issue after sitting and wont accelerate past no wake speed. Tank 1 has fresh fuel tank 2 has bad fuel, fuel filters have been changed. i am thinking his carb need to be gone through. i have a Q-Jet from a 5.7L that i rebuilt for another friends project that got scrapped. My question is can we bolt the 5.7L carb on and run it to see if its definetly a carb issue. We can swap a carb in a half hour. i would think a short run would be ok but a long high rpms run could run it a little lean. Of course and rebuild or repacement will be the final solution.

We have no idea of the serial # and i only know its vintage by the aluminum valcovers and its black so i assume a Merc engine. Apparently the boat was originally power by a crusader 440 chrysler engine. Who knows who cobbled this thing together. Its a really cool old boat and does make good beach house a the jersey shore.

 

[greno]

This is probably more likely an auto crate engine that somebody stuffed in there. People like to live dangerously.
First thing I'd do is make sure all the accessories are marine accessories. Starter, alternator, distributor, carb, etc. Don't want to risk fire/explosion while you're trying to fix the carb issue.