i just found out that one of my trucks has a 351 modified windsor. i didn't really no there was such a thing, i thought there was 351 windsor and 351 cleaveland. i was wondering if the modified windsor could match the 351 cleavland in performance, because i've always heard people talk down on the windsor motors.

 

It is either a 351 m or a 351 W. Two completely different engines. There is no 351 M/W that I have ever heard of. Please someone butt in here "this dose not compute"

 

It's probably a 351M. A 351m is basically a destroked 400. They came up with the idea to still offer a factory cleveland head 351, after the regular 351c was discontinued. These were a pretty common factory truck engine during the 70's.

Now a 351w could become a "clevor", by someone installing Cleveland heads at some point, but that would be a rather rare.

On edit:The 351m was a poor performer, being essentially a 70's low compression smogger motor. It was nothing like the 351c. A typical 351w would usually out perform it. The only thing holding back the windsor was the poor breathing of the stock windsor cylinder head, being essentially not much better flowing than a stock 289 head. With better breathing heads a windsor can be strong motor and it's whole lot easier than trying to get the M to perform better.

The M and or the 400 has plenty of potential in my opinion though.

The Cleveland head with mods on a windsor short block is not an easy slam dunk upgrade. The closed chambered C heads have such huge ports that they don't provide a strong signal to a carb at lower rpms, and the open chambered versions usually require a popup piston to get good compression. When the compression is high, the open chambered versions are more susptable to pinging..ect..

Today, a wide selection of aftermarket windsor heads offer an easy and inexpensive upgrade that is proven.

 

i have no clue lol, all i no is i went to the parts store to get some head gaskets. he said wat kinda motor is it, i said windsor. well when i got home the holes didn't fit. so i took them back and he was like," o you must have a modified windsor." so he gave me those gaskets and when i got home they fit. i'm only 16 if had this truck sence i was 10, just now trying to figure all this stuff out.

 

It's probably a 351M. The guys in the Cleveland forum can tell you plenty! If the waterhose goes to the front of the block instead of to the intake manifold it's a clevland family motor.

 

What year is your truck? The 351M/400 was put in trucks as late as 1982. The 351M/400 use the same heads as the 2V 351C. You should probably talk to the 335 series engine guys.

 

ya, i went and found this article on 351 engines. and i'm pretty sure i have a 351m. i think its kinda confusing and according to the article i'm not the only person that was confused about the 351 engine series. https://www.ford-trucks.com/article/...00_Engine.html copy paste this website its pretty cool.

 

its a 1979 f350

 

The 79 F350 had the 351M/400 in the compartment, but not sure on the other engine options. You can not tell much difference between a 351M and a 400 without measuring the stroke of the engine. Its not a bad engine but it is not a windsor by any stretch.