I'm rebuilding a 360 to a 390. If I keep the factory cam over replacing it with a Crane 343901, realistically what am I sacrificing? I am basically keeping everything stock with the exception of the KB150 pistons (already been running headers and duals).

 

About 10 horsepower. The torque is about equivalent, with the 901 extending the torque curve a hair higher in the RPM band. Really the stock cam isn't that bad, so long as it's in good shape. Plus, you have the advantage of having one that's already broken in to it's lifters, not having to mess with the non-adjustable valvetrain, etc.

What you probably should do, is get a good (aftermarket) timing set for it so you can set valve timing.

 

It's funny you should mention the timing set as I was needing to get one anyway. What is good here?

 

The Ford Racing one looks good, and has good adjustability. Summit PN FMS-M-6268-A390.

 

Why stay with a used thirty year old cam? That's the real issue. Another cam choice is Crane's two Energizers for the 390, the 272* is a good choice as well. More lift and duration and idles like the stocker.

 

Yeah... rebuilding an engine without changing the cam? :/

Are you trying to take my title or what? :/

Alvin the dumbest guy on F-T.com

 

Yeah... that's why I put that in bold. Chances are it probably isn't.

 

The stock cam IS in great shape. The motor had around 60K original miles on it and the reason for the rebuild is 2 failed connector bearings. I still may go with an upgrade but needed some info on some options as I'm getting a '76 F150 back from my son that's gonna need some work. It's amazing how difficult all of the fluid fill openings become so hard to find after these trucks leave home!

 

BTDT! :/

Do yourself a favor and cut your losses short, he's never going to learn where those openings are or how to "read" an odometer either one, until he puts his own neck on the stump. :( Just the way it is. :(

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I put a measly little ol' 252/252 Comp "enonomy" Cam in my 360 and it gets better gas mileage and has more power both. The fact that the power band is now in a more usable area is the best part really. No kidding on any of that the price of the cam, lifters and Edelbrock timing gears was worth it. But I intended to use those things up tho ;) it'd be different if you were looking the resell it soon?

At this point my engine has 75k on the rebuild and still runs better than it ever did and I bought the pickup new. :) The smog cam had retarded timing and who knows what else done to it. :/ There seemed to be no top-end limit (run out of carburetor tho) but had no bottom end power. At 31 mph the pickup couldn't pull itself against the wind or up a slight incline in 4th gear. Not sure where that limit is now, down in the teens somewhere. :)

The next best thing is to advance the timing on the stock(?) cam about 4 degrees. At least do one or the other? :)

Funny how that seems backwards, advanced for tractor-like power and retarded for dragster-like power, huh? :)

Alvin in AZ

 

About four years ago I put in a Crane 343901 in a 390 I was building. This was the result of sifting through a lot of FTE threads - thanks guys! The engine was a great runner - had a solid bottom end and pulled hard all the way up. When the truck was empty, acceleration was impressive, and when towing, it did very well even with a GCVW over 10,000 pounds.

There is already some good advice in this thread, but no matter what cam you go with, look at manufacturer guidelines on matching the cam to the engine's compression ratio. Other things are important, but the compression ratio is one you are not going to easily change after the engine is together. My engine was above 9.5:1 and it liked the cam. It would run fine on mid-grade gas, but I ran premium when doing heavy hauling just for a little more margin of safety. If you are shooting for a lower compression ratio for running regular gas, then you will want a little milder cam.

Alvin,

I also would like to be educated on cam timing. Following FTE advice, I put my 343901 in with 4-degrees of advance and was always glad I did, but understanding this is one "blind spot" in my knowledge base. Anybody have a clear explanation?

 

Keep in mind the '72 and up 360's cams are timed way off for "emissions"

If you changed the cam and the timing set, chances are you just zeroed-in the cam as opposed to what, 12 degrees advanced or something really crazy?

I'd love to hear from someone with experience putting a pre-72 timing set on a later 360, and how it helped (or didn't)...

 

Yeah, that's why I recommended a timing set with a lot of adjustment!

 

I'm currently running the Crane Cam 343901 cam with Keith Black KB 150 pistons bored 30 over. I'm currently running 86 octane with no pinging. I haven't tried the higher octane. The engine / cam has good low torque/power.

acheda, engine has installed the adjustable Coyles double roller timing chain . Fires right up every time.

I revved the engine once at higher rpm's and let the clutch go, too much power and torque and could result in the engine power breaking something in the drive train.

GO for the BIGGER CAM.

 

When explaining it, is it easier to just say "get a pre-72 timing set" or to buy a performance set (double-roller) and say "set it to zero"?

I checked out Napa, and their site shows for Cloyes:

'74 F250 w/360, C-3021K
'68 F250 w/360, C-3012K

Summit shows C-3012K as being 390 and 428.

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OK, this is getting dangerously off-topic.

 

Krewat, I ordered the coyles timing set, it was for a 1968 Ford Galaxie or Mustang with a 390 cid.