I know this question has been asked a million times in these forums, but honestly it's all starting to run together and it seems that it is very dependent on the individual situation. So here's mine.

I'm helping a young man with a 1981 F150 4x4 with a 351 Windsor motor and 2bbl Holley Carb and 4-Speed Manual Transmission. The truck belonged to his father who died while serving our country about 12 years ago. He will be 15 soon and we want to get the truck in shape as, of course, he will be driving soon. The truck had been sitting for a while because it just stopped running, a problem that plagued his dad even when he was driving it. We tracked the trouble to some kind of short in the electronic ignition system and got it running again, but it is not reliable since we didn't find exactly what is shorting so the problem comes and goes. We have decided to rip out the entire system and replace it.

Here is what we have:
Block Casting: D9AE-6015 (1979 Full Size)
Head Casting: D8OE-AB (casting date Feb 21, 1978)
Intake Manifold: RF-E1AE-9425-FA (1981)
When they bought the truck they were told it was a new motor, but obviously it is a rebuild and the quality of the work is questionable to me based on some of what I have seen. As far as I can tell everything is stock. We have already removed all the old ignition system and the intake manifold, ready to start rebuilding the top end. We'll run compression tests today.
Trying to work on a budget of about $1,600. May need to defer some things out for later to stay in budget.

Here is what we want:
A reliable vehicle that's good for the street and off roading so low to mid range torque and hp. Don't want to just go back stock so looking at replacing at least the Cam and Intake along with the lifters and springs and other necessary parts. Probably need to replace the heads as these seem to be the heads people say to avoid in regards to any real performance. I would like to put parts in that he would not have to replace in the future if he decides to do more improvements and beef things up more.

Here is what we are thinking of doing and where we need lots of help.
IGNITION: MSD Ignition system. MSD 6 Series? Which distributor is best?
INTAKE: Edelbrock Performer Intake?
CAM: Xtreme 4 x 4 Hydraulic Flat Tappet Camshaft? Part# 35-239-3, Grind# X4262H (Duration 218/226 at .050 lift, Lift .493/.512, LSA 111) There are four different grinds in this Cam with different duration and lift, do we want more duration or more lift?
LIFTERS: Hydraulic Flat Tappet? Which ones? Probably get them as a kit with the Cam?
TIMING CHAIN/GEARS: Double Roller? Which one?
HEADS: Don't think we can afford to go aftermarket here. Can anything be done with what we have to improve them. If we can find some Ford cast heads at a reasonable price it would be better to swap.
EXHAUST: Leave stock for now due to budget constraints, but what would be a good application when we can change them later?
CARB: Holley 3310 4bbl square bore 750CFM (I have this sitting around already)
I'm sure I've forgotten something here.....

We did a compression test and I don't think it looks good. This was a dry test with the engine cold. Six of the eight were between 95-100, one is at 85, one is at 45. I'm going to redo again tomorrow after I give the battery a good charge, hoping maybe I just didn't crank long enough. I'll wet test the one at 45 and see what we get.

This is my first time working on Ford. I've done lot's of work on Chevy's and a few others so I'm not a total newby, but no where near an expert.

Please, I would like to hear everyone's thoughts on what they would do with this motor. Are any of my suggested parts in the ballpark for what we want to do? Will they work well together? Will this stay somewhat future proof? We are ready (and eager) to start buying parts.

Thanks for any help.

 

I think if the compression test fails again with a cylinder at 45 PSI, a rebuild might be the best bet, although it could be something simple like a bad valve or head gasket. I'm no expert, but bottom line for that budget is a cam upgrade with full exhaust (long tube headers, maybe 2.5" collectors, high flow cat, then new Y pipe with 3" out and back). Mine is EFI so I don't know about the carb intake. You may have smog era heads which are restrictive. You may be better off grabbing a pair of E7TE heads off a newer truck or mustang, years I'm not sure.

Let us know about that test!

-Glaser67

 

Update: I ran a wet compression test on the two low cylinders and they both improved going from 85 up to 100 and from 45 up to 65. I ran a wet test on a cylinder that was at 100 and it had no improvement.

I think that means the problem with those two cylinders in most likely in the compression ring. If it were anywhere above the cylinder it would not have improved at all.

I agree it means having to do a rebuild or replace, but I don't think it is in the budget so I'll need to look at the alternatives, whatever those might be.

 

Ignition ? Don't waste your money on the MSD. There are better cheaper ways to go here. Like a simple stock points distributor fitted with an electronic unit and a hotter coil. Intake ? I'd go with a Performer RPM instead of the Performer. Go with the cam you listed above. Better yet would be an EFI grind with a wider LSA, these will give it a cleaner idle and give up nothing in the upper rpms. Heads ? I'd look for a set of iron GT40's (not the GT40P's) Or a set of E7TE's, then remove the Thermactor bumps from the exhaust ports. You can do this in 30 minutes (all eight ports) with a drill and a carbide porting bit. While at it, open up the walls and roof of the port to match the gasket.

 

You might look for a late model 5.8L to rebuild rather then rebuild what you have now. You may come across a mid 90's engine that has a roller cam or is at least roller cam ready. This will allow you to use the cam you have from your current engine or upgrade to a roller cam.


I have found that many EFI engines don't actually wear out. Usually something ease causes that vehicle to be "put out to pasture" and the engine is vary re-buildable.