'79 351m

[Boggin]

so i found another truck, its a '79 bronco with a 351 modified for $400
http://www.nlclassifieds.com/classifieds/Automotive/CarsandTrucks/Ford/224723

heres the link:
http://www.nlclassifieds.com/classifieds/Automotive/CarsandTrucks/Ford/224723


it says she has a rear engine oil seal leak. so i emailed him and asked how bad it was and he replied saying it is still useable and you just haul off the basepan and slide the seal through? how hard is this and how long does it take?
also do those motors have many aftermarket accessories? i dont want to highly modify it, i will probably first be getting a edelbrock air filter from summitracing.com, and whats the deal with changing carbs, how much difference does a edelbrock carb give you? or holley?
also will that truck have a d44/9"?
thank you very much

 

[Psychopete]

it says she has a rear engine oil seal leak. so i emailed him and asked how bad it was and he replied saying it is still useable and you just haul off the basepan and slide the seal through? how hard is this and how long does it take?

I'd be tempted to pull the motor for a rear main repair. I had one of these engines out of an '83 F150 in a full day. Could be done in a weekend or 2? Disconnecting exhaust will probably be the most troublesome. Getting the engine back up to the trans can be tricky. I don't remember the bell housing bolts being too hard to access.

also do those motors have many aftermarket accessories? i dont want to highly modify it, i will probably first be getting a edelbrock air filter from summitracing.com, and whats the deal with changing carbs, how much difference does a edelbrock carb give you? or holley?

There is some aftermarket, some parts can be swapped from a 351C (same engine family with dry lower intake manifolds). Do some searching around for aftermarket stuff and what you can use, cost is a bit higher on 351M/400M aftermarket parts compared to a 302/351W.

Pete

 

[Boggin]

k thanks man, and i dont really want to pull the engine apart, we will see what happenes once i can get her home

 

[LittleBigFoot]

There aren't many good and running 78 and 79 Broncos around. (The only two years they got big cubes and solid axles) If you destroy this I will find you.

I had a 79 with a 400m and the thing was a beast. It was already totalled but I salvaged the axles. I took out my frustration with a head wound on the rear quarter with a roofing hammer and could hardly dent it.

Check the radius arm C bushings and the pivot bracket bushings as soon as ya drag her home.

Oh, chances are the outer and inner axle seals have never been replaced so check those out too.

But remember, if you destroy it, I will find you.

 

[Boggin]

haha no worrys there man, this truck wont be abused, thats what i will keep the b2 for, and plus the bronco got the 351m so she wont be cheap on gas, so mostely a restor-er for when i get my lisence

amd STRAIGHT axles?!?!?!?!?!? are you serious?

oh and apparently the 351M is a 400? is this right?

 

[baddad457]

it says she has a rear engine oil seal leak. so i emailed him and asked how bad it was and he replied saying it is still useable and you just haul off the basepan and slide the seal through? how hard is this and how long does it take?
also do those motors have many aftermarket accessories? i dont want to highly modify it, i will probably first be getting a edelbrock air filter from summitracing.com, and whats the deal with changing carbs, how much difference does a edelbrock carb give you? or holley?
also will that truck have a d44/9"?
thank you very much

The rear seal can be fixed, but as for the mods you asked about? Doing any and all will be a complete waste of time. Only way to wake it up is to pull the motor, completely rebuild it and replace the crank with a 400 unit.When you get done, you'll have spent 5 times the purchase price of $400.

 

[fordmike1]

The rear seal can be fixed, but as for the mods you asked about? Doing any and all will be a complete waste of time. Only way to wake it up is to pull the motor, completely rebuild it and replace the crank with a 400 unit.When you get done, you'll have spent 5 times the purchase price of $400.

Dont listen to this guy as I have personally built these engines for trucks and have had great luck with them.This is the same engine block as the 351c with a modified block deck height(hence 351 "M").This engine has the potensial to make great power & torque just dont go looking to make it a race engine.Anything can make power if you spend the money to do it right.

 

[Boggin]

ok thanks man and i dont want to make it a race engine, nor do i want to highly modify it, ijust want some simple add ons to dress her up a bit

 

[85_Ranger4x4]

Dont listen to this guy as I have personally built these engines for trucks and have had great luck with them.This is the same engine block as the 351c with a modified block deck height(hence 351 "M").This engine has the potensial to make great power & torque just dont go looking to make it a race engine.Anything can make power if you spend the money to do it right.

Do whatever you did to your 351M to a 400 and look out.

Same exact engine but one has a half an inch less stroke, and really stupid tall/heavy pistons.

 

[Will]

It's not a modified 351C, it's a 400 modified down to 351" with a 351W crankshaft. It has the 3" mains--really need those in a 351. And since it's the 400 deck height, 351C intake manifolds do not fit. They used to sell a spacer kit to fit them but now they do make intakes for it. The heads are the same as the 351C 2V. And so are the camshafts and distributor. There's nothing particularly awful with it I guess. We had one in a '77 LTD II wagon when I was a kid. On those cold winter mornings in Iowa the pistons would rattle around in their bores--which I attribute to the tall pistons. The compression height is about .3" higher. They should have used a .3" longer rod. It's a hobbled together thing. But it did it's job--which was to lug around chrome-laden shitboxes.

A 400 crankshaft and a set of 351C-4V heads--that would be something. You can use 351C pistons as they have the same deck height, but the rod ends will have to be bushed. But it would be a great motor.

 

[baddad457]

Dont listen to this guy as I have personally built these engines for trucks and have had great luck with them.This is the same engine block as the 351c with a modified block deck height(hence 351 "M").This engine has the potensial to make great power & torque just dont go looking to make it a race engine.Anything can make power if you spend the money to do it right.

I've personally driven them in stock form and they're TURDS. 9MPG in a 77 highboy F250 with a 4 speed and 4.11 rear. It didn't have enough power to get out of it's own way. And bolting a 4 bbl carb onto a stock motor is a complete waste of time. THAT is what the question was about. It can be made to make power, but that requires rebuilding it with a 400 crank and a custom set of pistons to correct the deck clearance with the stock pistons (a negative .125" clearance makes for GREAT QUENCH with open chambered heads) And as Will & 85_Ranger4x4 both stated, this is NOT a modified 351C, it's simply a destroked 400 using a half inch shorter stroke crank and some very tall, heavy pistons. The whole thing was a quick fix for Ford to make up for the lost production of 351 cid motors after they killed the Cleveland. It was a bad idea then, and a bad idea now. If you want a 351 cubic inch motor, start with a 351C or 351W. Or even the old 352 FE motor. All of them would run rings around a 351M.

 

[DRanger024]

There aren't many good and running 78 and 79 Broncos around. (The only two years they got big cubes and solid axles) If you destroy this I will find you.

I had a 79 with a 400m and the thing was a beast. It was already totalled but I salvaged the axles. I took out my frustration with a head wound on the rear quarter with a roofing hammer and could hardly dent it.

Check the radius arm C bushings and the pivot bracket bushings as soon as ya drag her home.

Oh, chances are the outer and inner axle seals have never been replaced so check those out too.

But remember, if you destroy it, I will find you.

One of My buddies older brothers just parted out a 78 with a built 460 and a 4 speed in it. Damn thing sat next to his house un-driven for many years. Always started on the first crank though. Oh, and get this.... ZERO RUST! The only reason he parted it was for the rear end. Effin dumba$$

 

[fordmike1]

The Ford 400 engine was based on the 351 Cleveland but was produced with a half inch taller deck height to allow for a crankshaft with a longer stroke. The 400 also featured larger main-bearing journals and had "square" proportions, with a 4.0 in (102 mm) bore and stroke; it therefore displaced 402 cu in (6.6 L), making it the largest small-block V8 made at that time. It was introduced in model year 1971 with a full half-inch (12.7 mm) longer stroke than the 351 Cleveland, making it the longest-stroke Ford pushrod V8 engine. A long-stroke engine has good low-end torque. This was a good compromise given Ford's requirement for an engine to power heavier mid-size and full-size cars and light trucks. The M-block, as it later became known, was the last pushrod V8 block designed by Ford. The M-block also shares some elements with the Windsor engine family: bore spacing, cylinder head bolt-patterns and crankshaft journal dimensions

The 351M designation is commonly referred to “Modified”, and is derived from the use of both "Cleveland" (block, heads) and "Windsor" (crankshaft) components in the same engine. A "Modification" for the parts intended application so to speak.

And if you try to use the 351m crank in a 351w you would need to machine down the front of the crank so the 351w timing chain would fit.

 

[mhughes165]

idk about u guys, but i musta gotten a straight up FREAK 400 in my 78 f-250 (aka brown turd warrior) with the 400 in it, intake carb mild cam and full exhaust through the 4speed id put down a 14.23 1/4mi, and it had torque and balls for days, if anyone in the region doesnt beleive me i will arrange a ride in the truck and u will become a believer

the engine was built for a bronco intially, and i bought it when the HIGH mileage 351m took a shit on me

 

[85_Ranger4x4]

idk about u guys, but i musta gotten a straight up FREAK 400 in my 78 f-250 (aka brown turd warrior) with the 400 in it, intake carb mild cam and full exhaust through the 4speed id put down a 14.23 1/4mi, and it had torque and balls for days, if anyone in the region doesnt beleive me i will arrange a ride in the truck and u will become a believer

Most of the negative waves so far are directed towards the 351M... not the 400.

My dad has a 400 in his '80 F-350, it is a heck of a puller for what it is. He says the one that was in the truck before he got it would tear this one apart before it wore out. The PO had some work done to it, and said his friends first generation Cummins Dodge couldn't keep up with it on the hills hauling livestock to Omaha... and while it isn't too wild it isn't stock either.