Good, honest advice wanted.
 

Over the winter, I would like to perform a few modifications to my 7.4 MPI (310hp). Last winter I installed Stainless Marine exhaust, K&N arrestor and an adjustable fuel psi regulator from Vortec. I did not gain any rpm or speed whatsoever. A couple experts have advised I am tapped out with the MPI set-up.
I would like to scrap the fuel-injection ( I have a buyer for it) and install the following pieces:

Edelbrock 750 cfm Marine Carb
Edelbrock Performer RPM intake
Holley 110 gph electric fuel pump
GM ZZ502 (502/502) camshaft
.527"/.544" 224*/234*
GM ZZ502 valvesprings
Mercruiser Delco distributor (from carb engine)

My Questions:
Do you think I`m crazy for walking away from the injection?
Will I gain any rpm or speed from these mods?
Would you do anything different with what I have to work with?
...Please don`t tell me to sell the 7.4 and buy a 502. I want to work with this engine before I swap power.

As always, any comments good, bad or other are always appreciated!!!!

I would use a Merlin manifold, it has the brass inserts in the water passages. As for the rest, not sure.

DO NOT USE THAT CAMSHAFT!!!!! Get a cam that is for a marine application!!! Call Teague marine or someone that builds marine H.P. engines. If you go with that cam you will be sorry.

Also I recommend going with the Edelbrock Air Gap manifold. Makes better power at the mid and top end.You also might want to look at doing some port work on the heads as well.

leave this engine stock...well i guess if would rather spend more time working on it than using it????

i think your going to run into problems somewhere between the heads on the motor and that cam your trying to install.but i do know that you dont have much farther to go with the original setup....already been through that.........

one word ........Pro charger!

Isn`t the Merlin manifold an open plenum? Would this really be a good idea? I always run in fresh water, no salt ever. Do I really need those brass inserts?

The ZZ502 cam was actually recommended by a expert who frequents this forum.

As for the Air-Gap intake, just read a dyno report on one. I think I will go that route, looks like a great manifold!

I have spoke with a reputable performance engine builder, they say it will work just fine. I can even retain my factory non-adjustable valvetrain.

FOUR WORDS......

I CANNOT AFFORD ONE! :D :D :D :D