Hello everyone!

I'm new at this forum, and I have looked at a lot of posts dealing with 351M's and I still have questions about my topic.

First off: The truck is a 77 F250, has been in the family since new and has under 100,000 miles (i think about 93,000) oh its a got the heavy duty 4 speed (creeper gear 1st) The only thing we did to the truck was an igntion upgrade, and now it has had trouble working, and we disconncted it. My father doesn't really use the truck anymore (its been replaced by a 96 f150, all the goodies, and 300 six) and I would like to use the truck for myself. It always seemed like it was lacking power. I'd like to change that. Here is what I had in mind:

Using edlebrocke performer 400 intake w/egr (pa truck) with 600 CFM carb.
getting an RV crane cam kit?? is that the 266 one??? I don't know, i'd like to replace the timing chain & gears at that time.
I was thinking about getting better heads? or polishing the ones i have.
while I have the engine out, I wanna replace the rod & main bearings, oil pressure is a kinda low too, so a new pump (high flow)

The truck already has headers on it. About the trans, is there another trans I could bolt on to it to reduce highway rpm's??? if not the 4 speed is fine.

Thanks for your time!

 

In my opinion, the Cleveland-style heads on a 351M do not require machining just to increase your torque.

Secondly, if you are wanting pulling power (torque) for your truck, I would ask why replace the HD four-speed? That granny low gear is one huge torque multiplier!

An Edelbrock Performer intake manifold, part number 3771, would be great for your application, in my opinion. If you use an Edelbrock Performer 600 cfm carburetor, you will need either an Edelbrock number 8053 EGR spacer or an Edelbrock number 8017 with a Ford E4ZZ-9A589-E spacer for 4 bbl applications.

An RV grind camshaft will give you torque like you wouldn't believe! I used a Crane RV grind camshaft in one of my 400's and it was really a great deal more powerful on the bottom end!

What ignition upgrade did you all install, please? What is wrong with it now, please?
Perhaps if you post that information, you might find help resolving that issue, too.

If you are going to tow a heavy load, I would suggest going with a double-roller timing set. They are not much more expensive than a stock set and they are stronger. Double-check with Crane--or from whomever you purchase the RV cam--and verify their timing recommendations. Mine was to still be timed at 6* BTDC. If you are going to change camshafts, be sure to change the lifters as well!! As a matter of fact, you may well be able to purchase a camshaft and lifter kit from Crane for an RV style grind application. I know you can from Clevite, but I really did like my Crane set, too! With 93,000 miles on the engine, I would surely replace the timing chain and gears--that nylon camshaft gear MAY be on its last legs, anyway.

If you are going to change the rod and main bearings, I would recommend Clevite77 bearings, for they are quite good and will handle the higher cylinder pressures and the resultant higher loading of the rod bearings quite well.

As long as I was that far into the engine, I would change the oil pump, too, as you mentioned in your post. I am not sure about a high pressure pump, for the rule of thumb is 10 psi for each 1,000 RPM. However, a high-volume pump is really useful--especially if you will loading the engine with a heavy trailer to tow. I did paint my lifter valley with a slick epoxy-type paint to help speed the return of oil to the pan, for my pan was only a 5-quart pan.

Just to make an assumption, I would say your low oil pressure is mainly attributable to excessive clearance in the rod and main bearings. Therefore, changing them and adding a high-volume pump will take care of the pressure issue.

At what temperature does your engine usually run? How about when towing? Even though the parts catalogs show a 195* thermostat as OEM, you can get a 180* or even a 160* unit if you wish or need to do so. (Of course, your engine should run a bit cooler even with towing since your radiator doesn't have the added burden of cooling hot ATF.
If you want even more information, contact Bill_Beyer, the moderator of this forum; he is a walking wizard on 351Ms and 400s!!
I do hope this is helpful to you!

 

Ranger,


Thanks a lot! that really did help. Here are the answers to your questions:
From what I heard the heads on these engines flow pretty well, and I think i'll let them be.

Yeah the HD 4 speed is nice, I was wonding if the newer 5 speed would be better.....but from what I heard it was kinda weak....so the 4 speed will stay!

About the igntion first, we got a Jacob's RV kit. It in had with it the control box, which connected right to the battery using heavy gauge wires & fuse, a high out put coil, an incline spark amplifier box, and new 8 MM wires. The only hook-ups are to the battery "+" & "-" and two plugs that went into where they would connect to the stock coil.

The problem:
we have had problems with it just cutting out, completly stoping the engine, we would turn the key off and it would restart fine. This happened more than more. So we went back to the stock unit.....Are there better systems sold for this engine??? That have the whole distributor???

Good advice on the rebuild part, & the high-flow pump. I'm not sure what the PSI is, I haven't gotten my good gauge out yet to check, but I have feeling it is due to worn rod & mains. It does have that low end "knock" at low RPM & med-high loads, like a rod knock. Its just from it lugging down.
About the cam. Should I replace the springs too?? I know for sure I am going to get a better cam & lifters & the timing set you spoke of. Does Crane still offer that RV grind?? I was on their site last nite and didn't see anything about it.

2 more things....

About the EGR manifold set up, I wanna use a 4 barrle, and I need the EGR for PA, will have hender my power using that over the non-EGR....I need to find out if I can get away w/o it....also is the 600 CFM the best??? what about a 650 or 700??? vaccum secondaries right???

Last thing:

My uncle put heads on the truck....the type he used he had to remove the one cross member.....now I don't like this very much....Cuz I'd like to tow with this truck, and use it, and I don't think its a good plan.....I am either A, replace with stock manifolds and run duals. or B, find the RIGHT headers for a 77 F250 2 wheel drive, and duels of course (not too loud)

I think I covered it all, sorry it is so long
Thanks for your help!

 

Bone,

Are you looking for a distributor and coil in one package? If so, check out Performance Distributors DUI for Ford engines. Since you're doing all of this work on the engine, why not get it rebuilt and start fresh (upgrade to the 400 CI)?

Get a Weiand intake and 4 barrel carb (whatever suits you best).

Check out Torque1st's replies on the stock Duraspark mods (1/4" spacers to offset the box from the fender, etc.)...very informative and helpful.

Headers will increase performance if matched to the engine, but I'd try stock manifolds first (easy install/removal, cheap) and see if the performance is acceptable.

Good luck,

Chris

 

I'm reading this thread because I have a 1977 F250 with 351M and C6 automatic. I am installing the Edelbrock 600 cfm carburetor on the Performer 400 manifold that a previous owner put on the truck. I didn't notice any EGR. I see an AIR pump down low on the right side. Now I'm wondering if I ordered the wrong base adapter, even though I talked to the Edelbrock tech line. Guess I'll have to go to my shop tonight, and take another look at my Ford.

 

I believe it is most valid that the 4-speed is much stronger, more of a torque amplifier with its granny low, and better by far for HD usage than the newer 5-speeds. Our neighbor got rid of his 5-speed for that very reason and went to a T18. He has over 215,000 miles on the four-speed with no problems--and he tows really heavy loads!

I have heard mixed reviews about Jacobs' set-ups--from they are the best thing since sliced bread to they aren't fit to throw in a junkyard! Your problem sounds somewhat to me as if the control box is heat-soaking and cutting out; however, it also would seem to me that if it were heat causing the problem, it would take longer to recover and cool down and operate. I would consider the post made lower in the thread about the one-unit electronic set-ups. A lot of people in these forums use them and seem to be well-pleased with them.

If you are going to use the truck with heavy towing at highway speeds for extended trips especially, I would go ahead and change valve springs as long as I was in the engine. Crane offers spring kits with their cams and lifters as well. The canted valve design of the Cleveland-style heads does load the valve springs to some extent.

I put the numbers from Edelbrock and Ford in my post above showing how to make the 4V manifold emissions-legal in PA. If it were my engine, I would go with the 600 cfm carburetor.

Did you mean to type: "my uncle put HEADERS on the truck...he had to cut the crossmember"? I assume this to be the case. I would NEVER cut into a crossmember--especially on a truck that will see heavy usage--and towing does strain a frame and crossmembers! Headers do allow Cleveland-style heads to flow and breathe even better; however, dualling it out with the factory exhaust manifolds and an H-pipe will give you a torque increase over just a single exhaust pipe set-up. Even with headers, using an H-pipe will increase your torque @ lower RPMs.

I hope this is of some help to you!

 

Thanks again for your help

In response to the posts:

I don't really want to spend the extra cash and try to find a 400 crank, and then finding pistons for them. I think the 351 will fit my needs.
I was looking for a HEI type distributor with coil built in, but it doesn't have to be that way, I just want somthing that will work, and give a nice strong spark at ALL RPM's, even though I doubt it will get much over 4K revs.

I'm pretty sure he didn't cut anything under the truck to fit those headers, if he did anything he unbolted it. I haven't had a good look under the truck to see for myself. I would like to have headers and about a 2 1/4 pipe, with that H-pipe you spoke of, and I was thinking flowmaster 50's. I think 40's might be a little too loud for what I want. Other than that, I thank you for answering my questions!

 

If you want a quality aftermarket performance ignition system, check into the Davis Unified Ignition systems. They are very good--however, you, of course, must stay away from the racing 18-volt systems they offer.

In MY OPINION, the BEST all-around Ford ignition system was the 1974 SSI system that Ford first introduced. I truly feel it to be more reliable that either DuraSpark I or II. (I do not say that lightly, either!) I ran a 1974 400 with SSI for over 245,000 miles and never had an ignition component go bad. Now, of course, I did replace the cap and rotor--but not the trigger wheel, module, or pick-up. Nevertheless, as Torque1st has made in some of his posts, he has ways he has suggested to make the DuraSpark systems quite reliable.

I admit I am relieved your uncle did not cut into the crossmember. That had me quite concerned.

I have been trying to ascertain a Jacobs tech line or web address for you to contact them regarding troubleshooting procedures on their particular system. However, thus far, I have not found either. As soon as I can find them, I will surely post them for you!

Insofar as I am aware, nobody's performance exhaust systems/mufflers are as good as Flowmaster's. I know several people who have used them and, thus far, none of them have complained about any aspect of them--except for a few grumbles about the price.

 

I have finally found that information for Jacobs and for Davis Unified Ignition. I found them last evening but just as I was getting ready to post them, evidently, the system went down. I really am sorry for the delay.

Jacobs Electronics, 500 N. Baird St., Midland, TX 79701
www.jacobselectronics.com
1-800-627-8800

Davis Unified Ignition
2699 Barris Drive
Memphis, TN 38132
www.performancedistributors.com
1-901-396-5782

Again, I am sorry for the delay; I have posted this as quickly as I could. I do it proves to be at least some help for you!