Why a 400M?

[Backwoods]

Ok, big question here? What to do? I have a F150 with a 400 in it, and I am trying to figure out whether I want to build the 400, or get a different bellhousing and engine.I would like more power, but would also like as good of gas mileage as possible, (I know , dream on right) but in stock form I am getting 9mpg. I have heard things about the 400, like thin cylinder walls, bad bearings, etc?
I like the 400 in my truck, and it has always had plenty of torque, etc, but alot of people say, just get a 460 and be done, and others say change bell housings and swap in a 351W, and even, put in a small block chevy motor for more power and better gas mileage.
For one, I plan on having my truck forever, so I am looking for opinions for the long haul, the 79 Dentside is my choice of trucks, but as for powerplant, I am not real set on any particular on, Help?

 

[wizzard351]

chevy? no way way would i ever even think about cross breeding a truck like that! if you like the power of the 400 you'll love the power of a 429 or 460(i personaly like the 429 better) and if you drive rite the 460 will get close to the same mpg as the 400. back in the day we used to talk about the 351m and 400m and my bro came up with the perfect saying "M is for mistake!"

 

[UNRULEE]

Well you already have the 400, right? And you not going to be building a 500+ hp firebreathing monster, right (although you could even with the 400)?

IMO the 400 has a largely undeserved bad rap stemming from it's later, smog years. I can see why too, in '79 the hp output of a 400 was something like 156! Pitifull! But underneath all of the emissions crap lies a stroked Cleveland......and that's a force to be reckoned with. BTW, with fairly minimal work the original 400 in my '79 F250 is putting out over 300 poinies, it's not even trecognizeable as the same engine anymore.

I say stick with the 400, you treat one right with the aftermarket and you won't even recognize that original 400. Take it from someone who knows, not some of these people that haven't even owned or driven a 400 (not you Wizard, but I'm sure those posts are coming!).

 

[Backwoods]

UNRULEE, Can you tell me, can I expect about the same gas mileage as what I get now, or worse, and what would it take doing to it, to get it to 300?

 

[DNFXDLI]

Look at TMI's stroker kits.....and just to razz you...it ain't a 400M...just 400.

 

[chuck101st]

I have had quite a few 400's... I say stick with it. I bought a 79 Bronc with a 400 when I was about 18 and it had no oil pressure...rattled and clattered..I dropped the oil pan and threw new bearrings and a oil pump in it and it ran pretty much flawlessly for quite a few more years until it started to burn oil...

As a matter of fact...thinkin back on it now...I have owned 5 dents (including 2 Broncs) and all have had 400's and have never had any major problems.

 

[DNFXDLI]

This isn't the stroker...and is a good read:

http://www.tmeyerinc.com/400Ford.htm

 

[flareside_thunder]

Stay with the 400.....they are an underdog in their own realm...I had a 78 with one and that damn thing got 18 MPG city......and correct the 351M is the only one to get the deserved "M".....hell it was only detuned for emissions.

 

[mtflat]

Duncan made the point, but I'll underscore it.

If you can find a 400M you'd better grab it.......it's so rare it's non-existent!

I like the 400! I have parts for a warm one if I ever get it together.

 

[UNRULEE]

UNRULEE, Can you tell me, can I expect about the same gas mileage as what I get now, or worse, and what would it take doing to it, to get it to 300?

They key is, once you get a 4-barrel on there, is to keep your foot out of the other 2 barrels. Rumor is that the primarys on most 4 barrel carbs are smaller than the two barrels on the factory motorcraft 2150. If you can manage that you should see a slight increase in MPG's.

To answer the second question, to get to the 300 and slightly exceed it (according to desktop dyno ) here's what I've done........670 Holley Truck Avenger, CompCams 265DEH K-Kit (bumpstick, lifters, timing set, valvesprings and keepers), be sure to install the timing set straight up (the factory set is retarded to reduce emissions), Edelbrock Performer intake, DUI HEI ignition (yeah it's Chevy based ), Sanderson shorty headers into a 2.5" dual exhuast with dual straight through Magnaflow mufflers.

 

[flareside_thunder]

They key is, once you get a 4-barrel on there, is to keep your foot out of the other 2 barrels. Rumor is that the primarys on most 4 barrel carbs are smaller than the two barrels on the factory motorcraft 2150. If you can manage that you should see a slight increase in MPG's.

To answer the second question, to get to the 300 and slightly exceed it (according to desktop dyno ) here's what I've done........670 Holley Truck Avenger, CompCams 265DEH K-Kit (bumpstick, lifters, timing set, valvesprings and keepers), be sure to install the timing set straight up (the factory set is retarded to reduce emissions), Edelbrock Performer intake, DUI HEI ignition (yeah it's Chevy based ), Sanderson shorty headers into a 2.5" dual exhuast with dual straight through Magnaflow mufflers.

MMMMMM yummy........

 

[DNFXDLI]

If you read that write up on the 400 that TMI did...they are getting 390HP and 450 TQ on an engine dyno....sooooo....allowing for 15% drivetrain loss, that will net you around 330HP and 380TQ at the wheels...and a much more efficient engine that should equate to better fuel mileage as long as you keep your foot out of it.

 

[TexasRho83]

Had a 400 in my other SC and gotta say that it is just about as ballsy (sp?) as my 460 in my current SC. NEVER had a problem with it. Beautiful performance and if you wanna believe it or not, I got about 14 mpg on HWY running 36" TSL swampers.

I sure miss that engine, but my 460 will burn my 36 hawgs on dry pavement so I'm not crying too loudly

 

[O'Rattlecan]

I feel like I'm in the minority after seeing the results.....

I voted 351w for the sheer fact of part availability. If you want more displacement, just stroke it out to a 393 or something. The parts are just TOO easy to find compared to other motors. It's not *too* bad on fuel either.

Ryan

 

[smokeyb97]

Keep your 400 and do an upgrade.
Here's what I went with:
Had a 351M, installed a 400 crank, oem rods, Tmeyer pistons, Compcam 255DEH with lifters and springs, Cloye Timing set, oem heads w/new valves and seats, Edelbrock Performer 400 intake and 600 cfm carb, std. Melling oil pump, 1 5/8" headers and a FlowKooler water pump. It dyno'd 339hp@4300rpm and 478ft/lbs@2900rpm.

 

[Mil1ion]

first off... No M after 400

The 351M is a de-stroked 400

These two share what is called the M block and The jury is still out on what the M stands for. I think is stands for Michigan


The 351M/400/429/460 share the same bell-housing bolt pattern

If this goes to an automatic trans, then and if the 429/460 you get is from an 72 or older, the Torque converter has to match the early crankshaft journal.

 

[Mil1ion]

Read this about the 400.

http://www.off-road.com/trucks4x4/article/articleDetail.jsp?id=198751

 

[LEB Paul]

Just for Lee

400s are complete junk! They have oiling issues, thin cylinder walls, they over heat, blah blah blah

get a 385 series (429/460) motor and you'll be loving your truck even more everytime you get in it! The conversion motor mounts are cheap and the bellhousing is the same as well so no changing the trans.

 

[DNFXDLI]

Just for Lee

400s are complete junk! They have oiling issues, thin cylinder walls, they over heat, blah blah blah

get a 385 series (429/460) motor and you'll be loving your truck even more everytime you get in it! The conversion motor mounts are cheap and the bellhousing is the same as well so no changing the trans.

Bwahahahahahahahaha.....you are a chit disturber of the highest order Paul

 

[dragogt]

Bwahahahahahahahaha.....you are a chit disturber of the highest order Paul

In more ways than one, huh Paul.??