question about a 400m?

[Dragon]

Definitely change the timing set. That is the major killer. The Factory retarded the cam so get a good racing type double roller so you don't get the same retarded top gear.

If you disable the EGR the engine will get sick until you get rid of the factory carb. It is set up for that mix of exhaust and will be way out of tune. The smog pump only pulls one horsepower what is the real problem is the air injector tubes sticking down into the exhaust ports. There are fully functional smog motors out there that pull really good power. The cat does not restrict enough unless the cat is clogged to bother removing on anything but a race motor. Free up Cat horsepower by putting late model Hi-Perf Mustang front cats and each side. They flow really well and still yank the garbage out of the air.

The wife thing is why I can't stay married.

[68swb]

ok that all sounds good, i do plan on putting on another carb. and i know that the cat. is not as much of a power hog as the mufflers are, since the cats. flow more than that of certian mufflers. any who another question is what parts interchange to the "m" motors, i think that i read that some 351c or 351w parts will interchange? is that right? thanks again guys....

[Fattz7duce]

check this link out. this is where i would go for info for my 79 bronco. good info on the 351M and 400. built right they are monsters. i prefer the 351C only becuz its what was in my 79 Bronco and ran like a raped ape.

http://www.projectbronco.com/

[Dragon]

The 351 C had huge ports so it excelled in the higher RPM range where it could make horsepower and was lost in the lower Torque range where it's stroke to port size slowed the intake flow and starved them for torque. The Ms with their smaller ports could pull better low end torque.

[Hawkrod]

The 351 C had huge ports so it excelled in the higher RPM range where it could make horsepower and was lost in the lower Torque range where it's stroke to port size slowed the intake flow and starved them for torque. The Ms with their smaller ports could pull better low end torque.

Only the 351C 4V had huge ports, The 2V had the same heads as a 351M/400 with the exact same posrt size. Hawkrod

[willowbilly3]

The 351 C had huge ports so it excelled in the higher RPM range where it could make horsepower and was lost in the lower Torque range where it's stroke to port size slowed the intake flow and starved them for torque. The Ms with their smaller ports could pull better low end torque.

Only the 351C 4V had huge ports, The 2V had the same heads as a 351M/400 with the exact same posrt size. Hawkrod

So the 351M/400 heads have the "2" marking in the corner?

[Dragon]

I never saw a 351C 2V when I worked for Ford nor did I find one in the manuals I can look in.

[Hawkrod]

The 351 C had huge ports so it excelled in the higher RPM range where it could make horsepower and was lost in the lower Torque range where it's stroke to port size slowed the intake flow and starved them for torque. The Ms with their smaller ports could pull better low end torque.

Only the 351C 4V had huge ports, The 2V had the same heads as a 351M/400 with the exact same posrt size. Hawkrod

So the 351M/400 heads have the "2" marking in the corner?

70-73 2V heads may have a 2 or they have a dot like 74-? heads do. Hawkrod

[Hawkrod]

I never saw a 351C 2V when I worked for Ford nor did I find one in the manuals I can look in.

I can only assume you worked for Ford very recently after these were gone from the highway. When I was a service tech they were dirt common. As far as your books go I can only assume they are not Ford literature because the 351C 2V was one of the most common V8 engines in intermediate cars from 70-74 and was the base engine in Mustang Mach I and all Cougars. They are dramatically more common than 4V engines and I see probably 100 2V's to every 4V. The engine code for the 2V was H. The main difference between the 2V and 4V is the heads. The 4V has larger intake and exhaust ports, so the intake and exhaust manifolds are different from the 2V. The early 4V (M code) heads are closed chambers while the 2V (H code), CJ (Q code) and HO (R code) all have open chambers. The Austrailian 2V heads have the 2V size ports with the closed chamber, so it has low end torque and still produces power that is missing from other 2V and 4V heads. Hawkrod

You probably should have Googled it, from Wikipedia:
H-code
The majority of 351 Cleveland engines are H-code 2V (2-venturi carburetor) versions with low compression. They were produced from 1970 through 1974 and were used on a variety of Ford models, from ponycar to fullsize.

From http://vintage-mustang.com/topics/faq/3 ... eland.html:
The 351 Cleveland, on the other hand, belongs to Ford's 335 engine family. This thin-wall cast BIG SMALL BLOCK uses the smaller 14mm spark plugs, has a separate front cover (bolted to the block) housing the timing chain and routing water - so that water does not go through the intake manifold, features beefy main caps (wide enough to drill for 4-bolt mains), a poor oiling system, and uses different heads for 2V & 4V versions. The heads make all the difference and these fire breathing babies make this motor the legend it is. On the 4V, the valves are HUGE, measuring 2.19" intake and 1.7n" exhaust (don't remember exactly). Valves this large are only possible via a canted valve arrangement, forming what Ford refers to as a "poly-angle" combustion chamber. The valve covers are not straight - the front is flat and parallel to the ground, but a curve twists the rear parallel to the head. They are attached by 8-bolts and when removed, there is a 4 cast into the corner of the 4V and a 2 cast into the corner of the 2V (at least in 1970). The canted valves are the dead giveaway.

[Dragon]

1975 to 1976 1984 to 1986 better job offers lead to my departure.

My manuals are never joe blow's manuals but Ford only. Getting my collection of Ford manuals off eBay.

[fomocoguy]

I would change the cam, cam chain, intake, carb, and install headers and true 2.25" duals with a crossover. The cam should be mild since it's only got about an 8.0 :1 compression ratio, but it will be leaps and bounds better than the stocker. An edelbrock 4 barrel intake and 600 carb would do it wonders.

If you want to get crazy later you could install some Aussie heads and really wake it up!

[68swb]

this is all great info. i checked out the bronco project site and it also has alot of good info. thanks guys....

[LANCE65]

A set of Austrailian 2bbl heads would really wake up a 400. They are closed chamber with 2bbl ports.That will give you around 9.5-1 compression without changing pistons. Add a decent cam and intake,exhaust and that truck will wake right up. Good Luck.
-Lance