Hello I am currently starting my research into how to make my 400/C6/4X4 run a little better. It currently has a Weiand intake with an Edelbrock 4 Bbl carb on it along with headers. What I am looking to do is possibly replace the cam and timing gears. I am not trying to make this a huge horsepower engine or anything like that but to just have it run decent on the road. The engine has just over 100K on it. My dad bought it brand new and was run conservatively through the years. I have been reading in the forum about different non-stock cams and possibly replacing the valve springs. I just don't know what cam would be best for a "close to stock" running motor that will not break the bank. I would like to maybe get a good "RV" cam but nothing crazy. Any opinions provided would be much appreciated.

 

Stock springs are fine with an RV grind.

If you have 100k on it you've done well . I would suggest you not waste any time or money on it until you're ready to pull it and give it a full rebuild. at that time there are a few things you can do to make it a little better without major expense.

 

I ran an RV cam with stock springs...no issues. It was a Comp Cam bump stick. Made great power in the mid range. A new timing chain set will give it a nice bump in the butt dyno too. I'd also like to add that I did this in the late 90's before all the changes in types of oil..so I didn't have any issues with break in and wiping a cam lobe.

 

with you 100% do it when it gets a full OH

 

I am leaning towards this camshaft. There are so many timing chain sets. I have no idea which would be best besides not a really cheap one. Any recommendations?

Melling CL-MTF-2 Melling M-Select Torque Cam and Lifter Kits | Summit Racing

 

Cloyes is a reputable name...maybe Moroso too but I don't know off the top of my head if they make one for a 400. Summit Racing would have any and all you need. Jegs too. Just don't buy one with the crappy nylon gears. All steel is the way to go.

 

I'm still running a Crane RV cam & lifters with stock non rotator springs .... since the mid-late1980s. Mine is a 351M, a de-stroked 400 as I call it. It was called a "Fireball", but the exact same numbers are sold by others, including NAPA. Edelbrock calls it a "Performer-Plus" #2172. Mine has seen 4,500 rpm in passing gear a time or three, but 4,000 rpm is my self imposed limit.
In fact .... I just opened your link ... Melling CL-MTF-2 Melling M-Select Torque Cam and Lifter Kits | Summit Racing, and it too is the same grind.

A 4x4 is not hard to drop the oil pan and inspect rod and main bearings.

I use a stock DS-II ignition, but I did long ago add a Mr. Gasket (or other?) quick advance kit to the distributor (dialed in by a "seat of pants" drive, just acceleration, no top end crap), and so I set my timing at 34 or 35 degrees total timing at 2,000 or so rpm (which is well after the mechanical advance is all in), with vacuum hose disconnected at distributor and hose from carb plugged (shut off) , then I re-plug the vacuum line from distributor to ported vacuum for normal running. Just straight manifold vacuum sometimes lead to "run on" at shut down on hot days, but it doesn't do it with ported vacuum. I used a measure tape to measure my HB out to 40 degrees BTC, marked every 5 degrees or so (used a Dremel after ink marking the tape)

 

351M/400 questions ask T Meyer he is the guru when it comes to building them.

https://www.tmeyerinc.com/product-ca...land/351m-400/

https://www.tmeyerinc.com/engine-builds/

https://www.tmeyerinc.com/tech/

And some other selected reading for ya. https://www.ford-trucks.com/forums/1...l#post18718464

All torque specs for 351M and 400, print this out.
Camshaft sprocket bolt--------40-45 ft.lbs.
Camshaft thrust plate bolts---9-12 ft. lbs.
Crankshaft damper bolt--------70-90 ft. lbs.
Crank pulley bolts------------35-50 ft. lbs.
Cylinder head bolts---------step one--75 ft. lbs, step two--95-105 ft. lbs.
Distributor hold down bolt---20 ft. lbs.
Exhaust manifolds------------18-24 ft. lbs.
Fuel pump to engine----bolt 10-15 ft. lbs.-----nut- 14-20 ft. lbs.
Intake manifold bolts--------3/8 in. bolt--22-32 ft. lbs, 5/16 in. bolt-19-25 ft. lbs.
Main bearing cap bolts--------70-90 ft. lbs.
Oil pan bolts--------------7-9 ft. lbs.
Oil pan plug--------------15-25 ft. lbs.
Oil pump bolts-----------22-32 ft. lbs.
Fan to water pump bolts---12-18 ft. lbs.
Rocker arm cover bolts-------3-5 ft. lbs.
Rocker arm stud/bolt--------18-25 ft. lbs.
Rod bearing cap nuts--------40-45 ft. lbs.
Spark plugs----------------10-15 ft. lbs.
Starter mounting bolts----15-20 ft. lbs.
Timing cover bolts--------12-18 ft. lbs.
Water pump to engine------12-18 ft. lbs.

And the firing order for the 351C, 351M, 400 is 1-3-7-2-6-5-4-8

I have always hear that installing a timing set, timed "straight up" and not any retardation, will wake it up.

"Changing the timing chain makes a world of difference on the 351M. The stock chains are retarded 5 degree, and just get worse as they stretch. Get a 71' chain with no timing retard and they are completely different motor."

 

I "rebuilt" my 351 Measly a few years ago, it dropped a lobe and ground down a lifter, before I got 8-10 mpg, I'll have to find grind for cam, but it was a comp cam, lifters, pushrods, springs, new timing set (duh) Weiand intake, 500cfm Summit carb, it was a whole new funbox!! I now get 8-10mpg and the smiles per gallon are awesome, way better than before, if you have stock timing, just getting it set straight up will wake it up. And yes, call Tim, you can spend $ or $$$$ depends what your budget is. Plasti-gauge the bottom end, mine was great, go from there.

 

As other have mentioned, I wouldn’t open up a 40yr old engine with 100k to do a camshaft.
with an RV cam you are looking at 15 horsepower gain.

it would take

new intake manifold gaskets
timing Cover gaskets
timing chain
camshaft and lifters
valve cover gaskets (if yours are old)
carb gaskets
new coolant

etc etc

wait until you do a full engine rebuild when you have to do all the above anyway.

I would perform a leak down test to see what condition the engine is in. If the cylinder and head side test good then run watcha got with a good tune-up.

A cam swap on an old iron v8 (esp a RV cam) isn’t very noticeable like it is on a modern computer controlled V8.

 

Thought sure was just passenger car engines that got the retarded timing sets (for tighter emissions on cars) with narrower chains and nylon covered cam sprocket teeth (for quieter?) ...
... and trucks that got the straight up timing sets with wider chains and non-nylon coated cam sprocket teeth chain sets in their 351Ms & 400s

 

Wait till you can fix the oiling issues, and get the compression/quench right with aftermarket pistons and decked block. That will give you a bunch of power from idle to redline. That will be the time to throw a cam at it.

for now, spend some $15 to get the distributor tuned, buy this and put in place of the factory heavy spring. Flip 180* to lower advance slot (there will be two inside) while apart and set for about 36* total , this will make a nice difference in drivability. Work on getting your carb tuned right.

 

I opened up the 351M in my '79 over the summer. It was still original and had the nylon timing set with Ford stamping on it.

I know there is a lot of hate for the 351M/400 engines, but there are some advantages and they can be built into very strong engines. It will cost more than building a 460, but it weighs almost 200# less and bolts right in since that is what is currently in the truck. If you consider the cost of the components needed to swap to a 385 series engine plus the cost of the core engine you would need to source and rebuild, you might find it is less expensive in the long run to build what you have.

There are a lot of parts that interchange with the 351C as well. The 351M/400 is essentially a tall-deck 351C that was meant to replace the older FE engines and the BBF engines, but it hit the market at the wrong time and was turned into a boat anchor due to smog rules. Their reputation has suffered because of that.

I went with a cam that has the same specs as the Melling MTF-2, that cam is offered by many manufactures with the same exact spec. I went with the Summit Brand since it was in-stock at the time. Melling, Crower, Howards, Elgin, Edelbrock all offer the same cam with same numbers. In reality they all probably come from the same foundry and cam grinder and are just put in different "manufacture" boxes depending on which vendor orders it from the cam grinder.

There is one small issue with that cam, and that is the over .500" exhaust lift. From everything I read, if you try to run stock exhaust springs with the rotator cap/retainer that are installed from factory you will run into spring binding issues. You can still use "stock" springs, but you need to get new retainers and keepers, at least for the exhaust side, to avoid any problems. If you keep spring pressures low and near factory settings you are less likely to wipe the cam during break-in. Failed lifers and wiped lobes are still possible with any flat tappet cam but keeping spring pressure down and using a proper high zinc break-in oil can help mitigate potential failures. If it is in the budget a roller cam setup would be better.

A 4 barrel intake & carb, combined with better cam and double-roller timing set really wakes these engines up, but they still suffer from low compression which can only be fixed with new pistons and/or aftermarket heads. Tim Meyer has pistons to bump the compression up with factory heads which is what I chose to do. I still need to determine deck height once I have my engine back together, but I should have 9-9.5:1 static compression with the KB pistons I am using. That's about the max end of compression for factory open chamber heads that you can run and still use pump gas.

The exhaust already flows pretty well with factory heads and doing a little clean up of the exhaust ports and exhaust manifolds would work or you can opt to go with headers and the headaches they bring.

I am in agreement with others that if you are opening it up to do a cam, do it right and rebuild the whole thing. Dropping a fresh cam and timing set into an engine with 100k on it (regardless of how it was driven) would be like hanging a nice chandelier in a condemned haunted house...

You can find other 351M/400 builds here - https://www.ford-trucks.com/forums/forum54/

When it is no longer winter in my neck of the woods I will be adding more detail to my build thread for my '79 regarding engine reassembly and break-in. That won't be until May time frame though. It started as a 351M but I am replacing the crank with one from a 400 and it has been over-bored .040" which will put me at 410ci when all is said and done.

 

Interesting, but by then were they putting cats, etc on the F-150s? Just wondering.

I know mine has non rotator springs, all 16.

 

Yes, '75 was the first year cats were installed on F100/150s I believe, but I think that was only the CA emissions trucks and only on F100/150s. I am thinking late 77 maybe 78 model years all the F150s got cats but it wasn't until later years they were installed on the 250/350 trucks.

My '79 would have had a cat from factory but it long ago fell off somewhere on the road when a previous owner had it.

Mine did still have the charcoal canisters on the frame but those have fallen off recently and it doesn't have an air pump or any remnants to indicate there ever was one on this truck.

The intake had been swapped by PO to a Weiand, but the original intake was on the passenger floorboard when I bought it and it has the EGR plate still on it if I recall correctly.

Mine did have the rotator cups on the exhaust valves but those were removed when I disassembled them. They have since been worked over by a local machine shop and reassembled with all new components.