Hey everyone. I am pretty sure I will be bying a 1975 xlt camper special 2 wl drive truck tomorrow. I have already took it for a test drive. runs super and drives very true. The gentleman I am buying it from bought it from someone else. when I asked him what size motor it was, he just said it was a big block. He said 390, but how can I be sure. thank you for any input on this....

 

No way to get close without pictures and the VIN number. The VIN will identify what the engine had when it came from the factory. There are other clues on how to tell what a motor is, but I cannot remember them off the top of my head to repeat here. If you do a search, you will find some great hints on how to tell what you are looking at.

[edit] search with retsin, two mints in one.

2 bolts the engine is a: 239/256/272/292/312 (produced from 1954 to 1964)
5 bolts the engine is a: 332/352/360/361/390/391/406/410/427/428/ (FE engine)
6 bolts the engine is a: 221/260/289/302/351W
7 bolts the engine is a: 429/460
8 bolts the engine is a: 351C/351M/400

There are other ways of identifing the difference between a 302/351W, and a 351C/351M/400.

The 351W and 351M/400 both have wider intake areas than their smaller brothers. I don't remember an exact number, but I do know they are about 2" wider. This is because the motors have a taller deck height to accomodate a longer stroke.

*most* 2 barrel Clevland heads(also used on the 351M/400) will have a 2 cast into the upper corner, right below the valve cover sealing area, 4 barrel heads will have a #4 cast in the same position.

A 351W will also have a rib on the block between the top of the belhousing (top two bolts) and the lower intake sealing surface.


More help on narrowing things down. A 351C will have a sub 5" distance(4-7/8"?) between the top bell housing bolts, same as the late 302/351W. The 351M/400 will have about 7" between the top bolts, just like a 460. NO, that does not make that motor (351M/400) a big block, it only shares the pattern, and a few parts with the 429/460.

The 400 started production in '71. It looks alot like a clevland, because the design was copied. They changed a few internals, and used the same style head as a 351C.

It is difficult to tell the difference between a 360 and 390. The only way to tell is to measure the stroke. The 360 had a 3.5" stroke, the 390 around 3.75" stroke. The bore size is the same.

The 351C production ended in '74, a 400 was destroked to 351 to take its place (4" to 3.5"). The 351M/400 was terminated in '79 in cars, and 82 in trucks.

Certain 351M/400 cast before 1977 had problems with cracking in the lifter valley. I dont have the casting number handy, but it was only blocks cast at a certain foundry that are affected. If anyone cares, I will look it up.

Certain rare '72 400 blocks have both belhousing patterns, for big blocks, and small blocks.

429 and 460s, no way to tell from the outside on what you have, have to measure the stroke as well.

 

Super easy way to tell Windsors from Clevelands is how the top radiator hose attaches.

Windsor the outlet is on the intake manifold.

Cleveland (351C, 351M, 400) outlet on on top of block

 

the 460 comes out of the top of the intake manifold.

 

No 351M/400's installed till 1977 in F Series trucks.

These engines (and 351C's) have 8 valve cover bolts / Fuel pump bolts to the drivers side of the block as there is no timing cover, just a flat plate.

The pump also bolts at 12 & 6 o'clock, the only Ford 6 or 8 cylinder fuel pump that had this configuration.

351C = 1970/74 passenger cars/Ranchero's only. The 1970/72 4 bolt main version had sand casting problems in the valley area. > >

Ford sent all the dealers a Campaign Letter, advising us of the problem, said to pour this: C6AZ-19554-A .. Metallic Plastic Sealer into the holes! I KID you not!

1975/78 351M's & 400's had a serious problem with cracking heads. (351M: introduced 1975, used in cars only till 1977).

1000's of heads were replaced under warranty, 1000's more were replaced "customer pay" as the warranty back then was 2/24.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1975 F100/350 engine availability / The engine code is the 4th digit of the VIN.

B = 300 I-6 / F = 302 2V / Y = 360 2V / H = 390 2V / M = 390 4V / A or J = 460 4V.

360/390 = 5 valve cover bolts / 302 = 6 valve cover bolts / 460 = 7 valve cover bolts.

302 = F100/150 only.

4WD: 300 I-6 or 360 2V.
~~~~~~~~~~~~~~~
1968/76 360/390's share the same bore: 4.05" / 390's used different pistons, rods and crank than 360's / Stroke: 360 = 3.50" / 390 = 3.78"

Caveat Emptor: On sale day, 360 engines magically become 390's.

 

As Bill mentioned 360s always seem to magically gain some stroke and become 390s when they are being sold so if you determine that the engine is in fact an FE and the vin says 360 but the guy says it's a 390 the only way you can verify is measure the stroke. A 360 is 3.50" a 390 is 3.784" (just a hair over 3-3/4 if just using a tape measure) externally you can't tell the difference otherwise.
since it's a 2wd a 390 is possible so verify with the vin.

 

you could always ask the truck what size of motor it has? just joking! i know from my experience with my truck, the previous owner said the 302 he was giving me with the truck, was a 80s 302 out of a truck and was a slightly used rebuild? well i ran the engine block vin number and it turns out it was out of a 1971 ford torino!, i was happy to find out that 71 was one of the last good 302s, before all the smog mods and lower compression, the code i found was near the starter, and you had to look straight up at it from the ground, i am not sure about any other motors like the 360/390s or any other ford motor, as i only have had one truck! and its my first vehicle!, and on that note the 302 was clean as a whistle! i was glad, and the motor looks mint, i have only had it idle due to the fact its sitting in my truck which is in frame off resto right now, and i am sure someone can tell you a location on other motors where there is a engine vin number. i am sure they all have them? any ways best of luck and make sure you are buying what you think you are, as mentioned before a lot of 302s become 351w's and 360s become 390s and 351ms become 400s! when the truck is for sale! the bigger the motor the more money they think they can get! watch your back!

 

welcome to FTE!

well you said it was a 1975 camper special. that means it should be an F250 which would rule out 302. also it should rule out 351M/400/351C.

I know it's just me, but I always thought that the 351C was part of the 302/351W engine family......maybe I always thought wrong.

the easiest way for us to help you would be for you to post the VIN #.

 

nope the 351C is part of the 335 series engine family, the 2V version shares the same head as the 351M/400, and same waterpump, cam, timing chain, dampener, and flexplate/flywheel. But it does use the 302/351w bellhousing and motor mounts

 

If he doesn't have anything to hide, he'll give you the VIN.

 

Hey thank you everyone. It has the 390. I love it.