I own a 1998 checkmate 25'3 convincor with a 7.4 L motor 454carb/300 HP I want to swap it with a 502 mag fuel injection motor complete unit. I know how to read a manual and turn a wrench, aka busted knuckles ha-ha! What does this job take? is it a complete swap , or do I need extra parts? I live in Phila, Pa.area, any really good shops around me or in NJ?


Thanks in advance!

teh big pain in teh ass on that job is moving the engine. I pulled my engeina few months back and have it out for work. The switch shodul be esy as long as you have teh right tools. IE a lifting gantry or a fork lift or a really big cherry picker style engine hoist

Do I need a new wiring harness? or anything like that?
fuel pump?

You will probably need to rejet the carb if you are going to use the one that came on the7.4. Otherwise you will probably be too lean. Is it a Carter, Holley or a Q-jet?

going for a carb motor to a fuel injected I know you need to run electric fuel pump. I believe you also need a return line to the gas tank. I don't know if you can add the required wires or need a new harness.