EFI conversion for 351w

[bswedb01]

I have a EFI system for a 75 351w. Anyone have any wiring tips. I have the whole harness and computer. I forgot to get the EFI distributor. I also have the cruise control module, but don't have the stuff for the column. Any tips? Also the 351w has a 280 duration cam. Will it smooth out with EFI?

[fordman]

the efi dist and the older dist are different lengths. they will not interchange between older and newer blocks. you will have to look for an aftermarket one.

[RTG_RACING]

Forget about a 280 can with that efi setup. The best chance you have with that cam is to get an efi system off of a 5.0 mustang with the HO motor. The get a 351w truck lower intake. Port match the lower to upper. The should be a close match.

[bswedb01]

Could i still use the wiring and the computer? Maybe aftermarket EFI system? How would it run with a 280 cam and stock 351w EFI. I just want a nice street motor with desent milage.

[RTG_RACING]

Could i still use the wiring and the computer? Maybe aftermarket EFI system? How would it run with a 280 cam and stock 351w EFI. I just want a nice street motor with desent milage.

The computer in that style of setup wont be able to keep up with that kind of cam. I dont think it would run all that great.

[averagef250]

What year is the efi stuff from? 96+ should be sequential MAF like the 5.0 HO motors, but still will not run that cam. All the older truck efi stuff is speed density. You cannot possibly get it to run right with that cam. It relies too heavily on manifold vacuum for input and you won't have enough.

My advice is use the lower intake you have with an upper for a single throttle plate/MAF sensor, get some 24lb injectors, get a manual transmission 87-91 or so 5.0 mustang EEC and harness or buy a new harness from ford motorsports or anyone else who makes them and get a tweecer to tune it to the engine.

You will have a lot of money tied up into that or you can run the stock EFI 351 cam and use all the stock truck stuff. On that note, the truck 351 injection sucks IMO and is not much better than a 600 holley and duraspark.

Fordfuelinjection.com has a plethora of EEC-IV wiring and install tips.

[bswedb01]

I'll probably go to a smaller cam. Do you thing a 268 would be OK. I want a little rumble but will drive it everyday. I want to get good mileage and to be reliable like a newer truck. I am rebuilding the whole truck from the ground up. I have a 1970 f100 ranger xlt with all the factory goodies plus factory ac so I am making a truck that the wife could jump in. As far as trans I have a rebuilt C6 with a mild shift kit. I want to go for mileage so I am thinking 5 speed or AOD trans. I will be towing with it some about 4000-6000 pounds. What would be a good way to configure this truck?

[averagef250]

Again- your questions cannot possibly be answered unless you specify what your the EFI is from. Your first post says it's 1975 EFI. This is clearly WRONG.

You do not need to be a rocket scientist to build a good EFI setup, but you absolutely must understand how the crap works and why you cannot do certain things.

NO, NO, NO you cannot run a non-stock cam with speed density EFI unless you dump a fortune into tuning it and for what? A speed density bank injection EFI system? Go buy Holley projection GM TBI, dump it on and get nearly the same thing.

The EEC-IV stuff that is very moddable and tolerates modifications is MAF sequential injection used on the HO 5.0's and the latest 96+ truck engines. MAF is pretty easy to spot because it has MAF sensor mounted in the intake piping before the throttle body.

The only thing 87-95 speed density truck engines are good for is to swap them in entirely stock or with minor mods like emissions deleted and a slightly better flowing exhaust. The stuff is not adaptable and it certainly is not performance geared.

If you want to tow 4-6000 pounds regularly get a 300, 390 or 460. No offense to 351 lovers, but I've never been more dissapointed in an engine with a little weight behind it.