I'm not sure this is in the right section, but here goes.

I have a 92 flare side with a 5.0 that has a knocking rod. I thought my stepson wanted it, we were going to swap in a used motor, but he doesn't like it so I want to turn it into a toy.

I looked at Summit and they have a 390 HP 306 crate motor. What issues would I run into putting the factory EFI on a motor with this much power? I'm almost certain bigger injectors would be needed, but what else. All of the rods I've worked on in the past have been carved, so I'm totally green on taking a fuel injected motor beyond stock.

The only concern I have is with the fuel delivery, and I do plan to buy a crate engine since my time is very limited.

Thanks

 

I can almost guarantee that crate motor has a cam that will not work with Speed Density, even with a customer tune. I see a MAF conversion and a tune to get that 390HP out of it. 19 lb. injectors are too small and I would question whether the stock fuel pump(s) can keep up.

The stock truck intake may now be a bottleneck and for sure you need long tube headers. Then the rear end and stock transmission start to become susceptible to a high HP engine.

One thing leads to another....

I think it would be a great project but you need to address a few items to ensure the engine will live a long healthy life. Once you start getting traction then the stock drivetrain becomes a liability.

 

The drivetrain won't be a problem, I already have the neccesary parts to beef that up.

If it is going to be a huge problem to get a motor that strong to run with the EFI setup, how hard would it be to ditch that and use a carb? The tyranny is not electronic, use a mechanical or aftermarket fuel pump, mechanical gauges and do away with the engine electronics. Would that work?

 

I am not a fan of downgrading to a carb. Yes you can do it, it's your choice. The computer does not control the dash gauges, they are analog. If you take out the computer then you also need to change the ignition system.

 

It's a toy. He is not looking for better gas mileage so ditching the EFI for a carb would be a great idea.

OP, if you're up against the clock, just put a carb on it, set up the ignition how you like it, and have fun!

You can ditch all the computer stuff. The speedo will work as long as you leave the wiring to the VSS (on the rear axle) intact, and the oil/temp gauges will need to have their factory sensors installed on the crate motor. Voltmeter will be fine, all it needs is power. Fuel gauge needs the level sensor in the tank so even if you remove the EFI fuel pumps, just leave the level sensors in place in each tank. The tach SHOULD work wired straight to the coil, if its set up the way I think it is.

 

That's a lot of work to get a toy built. Pull a JY 5.0 and rebuild it how you want it. If you want it to work with the current speed density stuff, the build has to be fairly mild. If you want a fun toy with some real grunt, a MAF swap would be really easy with all the MAF 5.0's in junkyards, and that would let you buy a crate motor, or build whatever you want. Wouldn't have to fun around with all the guages, fuel pump bs, and any other electronic swap stuff you would have to do if you went to a carb.

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Thanks for the replies, guys. Yes it will be just a toy, nothing else. The thought hit me while I had some downtime at work, and no access to a computer to search like I wanted to.