im looking for real world experiences with the summit 5200 camshaft for the 400M 351M 351C.

how does it run in a truck?
what's the idle like?
how does it perform while towing?
what did your fuel mileage do?
how did it affect the vacuum?
how much more power is on tap? and where at as far as RPM?

I don't have a 400, ive got a 351C in need of a camshaft.
I know theyre different engines,. so results wont be exactly the same, but since its the same cam in a 400, I thought id ask around. since there were tons of 400Ms in the trucks.

ANY feedback is appreciated. I need to get this truck running soon. so I have to choose a cam fast...

A stock replacement cam is $95, or for an extra $15 I can get the summit 5200 cam and lifter set...
heres the 5200 next to a stocker. http://www.summitracing.com/compare

 

Well, I can't be of very much help to you as the cam I got for Buford was custom ground for that application, but, you should give Tim Meyer a call at TMeyer, Inc. (google it) and he'd be able to point you to a good cam grind for your 351M that'll serve the purpose.

Another option is to go to the 335 class engine forum here and search for cam grinds. I'm sure there are a bunch of guys that have discussed this very subject previously, and perhaps that Summit part has been discussed before.

By the way, just for your own edification, there was no such thing as the 400M. There was a 400, which is just a tall decked 351C. The reason for this, is that there was no other 400 cubic inch motor from Ford, so it had no need of a designator letter to delineate the differences between it, and other 400's which didn't exist. The 351M, on the other hand, makes more sense, as there were the 351C and 351W that came from the factory as well. As to what the "M" stands for is up for debate, as I've heard arguments for both "Modified" and "Michigan". The reasoning I personally have to call it "modified" is that the motor is a de-stroked, or 'modified' 400, having reduced the stroke from 4.00" to 3.50" in length.

 

I've heard more than one person call the 400 a 400m before. Actually, most of my parts guys call it a 400m because it is built off of the 351m block (they call these the M block motors). So even though there was only one 400 in fords lineup, its often called an M block because of the 351m that it was built off of.

 

Correction: 351M was built off of a 400. The 400 came first; the 351M came a few years later after the 351C was dropped and the 351W could not meet demand on its own.

Behemoth nailed it. Regarding the original post:

That's not a very specific question. Questions like "what is the idle speed", "how much vacuum does it pull at idle," etc are examples of specific questions. Any stock production engine should idle smoothly if properly maintained and tuned.

What do you mean by that? Are you asking for a number? That's not a factor of the engine family; again, that's a statement about how well the engine is maintained and tuned. Any stock production motor should hold 19 to 21 inches of vacuum at idle. Note that an engine doesn't "affect" vacuum, as if vacuum is some sort of pre-existing entity on which the motor has an effect. The motor makes the vacuum.

 

Ok thanks that makes sense.

 

ive always seen, heard, refered to it, as a 400M,
anyway, im just looking for whether or not guys who have this cam or one similar would reccomend it...

just like a before-after comparison.

 

I have this cam and it is a great factory replacement in my 351M. Smooth idle, plenty of vacuum, good fuel economy (stock compression), and a noticeable torque increase (butt dyno). I haven't towed anything with this truck yet as it is still being restored but I have driven it a few times. Sorry I don't have any concrete numbers for you, this is all off the top of my head.

On a side note, Ford has referred to the engine designation as a 351M (MODIFIED) AND 400 since the mid eighties in its SVO catalog. Here is the latest nomenclature from FRPP:

 

thanks jredline, thats the kinda answer i was looking for.