I have a 1990 F-250 with a 351W EFI and manual trans.

the speed density and batch fire injectors paired with the EECIV is a very limited system when it comes to increasing air flow, compression, and fuel.

My plan is to buy a TWEECER and a base tune for the truck for future mods.

After this I plan to add a larger Throttle body (twin 61mm or 56mm) not sure which one yet. A ported stock lower and upper intake, and ported stock E7 heads. I had to buy a long block recently so my engine has less than 5,000 miles on it. I want to leave the bottom end alone. Looking for Torque and Horse numbers in the mid 300’s range. One issue I am faced with currently is the stock compression ratio which is 8.8:1. Do any of you consider the above plan to be realistic and cost effective? I have not looked at cams yet till this is figured out. As far as exhaust is concerned I have Summit Short Tube Headers (1.5” primaries to 2.5” collector) 2.5” downpipes to a single 3” out to the back. I still have not sized fuel pumps, larger injectors and ignition/spark. I am not trying to reinvent the wheel here.

TLDR: Advice on Building a budget friendly EFI power plant (no computer/tuning advice)

 

Lose the e7s for a set of gt40s will be your first best upgrade.
shorties are minimal hp upgrade but better than manifolds, long tubes would be better. Other than that the cam is going to be based on what rpm operating range you will need the power to be in.

 

X2, the e7s gotta go.

 

Okay, I’ll see about some GT40’s, ported or not ported? also a port job on the lower and upper stock intake looks to be way too involved/pricey. I Could pick up a carb-style EFI intake instead for around $400. It’s Operating range is a little high for street starting at 3500 rpm.

 

Is there a good long tube header out there? Something made of stainless? Are long tube headers that much louder than the shorties?

 

I wouldn't port the GT40's. If you start throwing money at them, you'd be better off with a better flowing pair of aluminum heads.

 

Different types of headers will not make it louder or quieter. That's a function of the muffler. Short tube headers make less power, but they're useful in applications where a long tube won't work, generally because of clearance issues.

 

I would probably agree but if they are not interested in putting a cam in it, is there that much of a difference? Might save a lot of money getting junk yard heads and massaging them a bit. It's not what I would do, but I can see it being done to save some $$

 

If you're going to port them at home, that's not a bad plan, but if you're paying someone to port them, you'll end up spending as much as you would on aluminum heads or perhaps more especially if you need valve guides, valve job, magnaflux, decked, etc.

 

The factory flat tappet cam in the engine now is very tiny and restrictive. Adding any extra airflow pieces will be stifled by the cam. Best suggestion is swap that first.

 

you’re right, just saw the pricing for a pro porter on gt40’s. Definitely too much for my budget. However he does port upper and lower truck manifolds for $400 -Bigdogs Porting on Facebook and Youtube.

 

do you have a recommended camshaft that is flat tappet friendly, works well with stock GT40 or GT40P heads and is a good pairing with a stock ported upper and lower intake? Maybe a B303? Let me know

 

Any production SBF head is not worth the hassle. Since on budget look for old Edelbrock Performer heads or FMS GT40X. Better chamber, bigger valves, etc. Basically will make more power with less work.

I would look for headers with larger primary tubes.

19lb/hr sticks will support 275-300rw. The stock pumps are the issue with volume.

Pass on a larger TB unless you invest in heads and open the intake manifold up. Surface area of the dual ~49mm is not your restriction. Even then, probably worthless. I have a dual 61 as snagged cheap.

Best part of your build is you are starting with a 3.5" stroke

 

What vintage is the engine that you bought? Do you know the block casting number?

As mentioned elsewhere, the biggest bottleneck on these motors is the factory cam, it's so bad that with the early motors('93 and older) it is almost a total waste of time and money to do any other mods until a better cam is swapped in. The E7 heads and stock truck intake are not performance pieces but believe it or not you can have a 275hp motor with nothing but a cam change, and this is possible with the stock EFI system you just have to use a mild cam that produces good vacuum. The Crane 444232 was one such cam that was a popular upgrade on the first gen Lightning, have a look at the specs for it and you will see what I mean. I had that cam in a 5.8 I built for my truck and it did perform very well and ran as smooth as stock... which is what is necessary to work with the stock tune.
If you then add better heads and intake the motor will move lots more air and that will exceed the supply/control limits of the factory fuel system so bigger injectors and pump are necessary, and that in turn requires tuning. There are 2 main options now the Tweecer and Pimpx, a Tweecer is relatively cheap but it is very technical to setup and use, to make the most of it you want pretty good computer skills and it wouldn't hurt if you have an electronics education background as you need to understand how the EEC processor works and the logic behind the programming. The Pimpx is more user friendly, it completely replaces the stock PCM and is natively tunable but the upfront cost is much higher, still I think this may be the better option for anyone that plans on doing successive upgrades.

 

[QUOTE=Conanski;20829520]What vintage is the engine that you bought? Do you know the block casting number?
I found the casting numbers on the back above the starter. I need to remove the starter and clean up the numbers. I will do that tomorrow and post them here.