sel

they were chocked to death with primitive emissions provisions in the heads and manifold to werent they..

FOMOCO466

I have a good article on a guy who made his 351M run bad *****, blocked off the oil galley, worked the dist, and ported the heads, then installed the biggest two BBL carb he could find.... it's something with the designing of the heads they were designed for 2bbls carbs to work the best.

I ran a performer intake and a 650 edelbrock carb.... had a 750 on it for a while..... after I replaced the cam before doing the entire rebuild, I put a 4bbl to 2bbl adapter on it and slapped my 750 off of my 460. Tuned it and hit the road.... 3:50 gears, 35in goodyears and I was doing about 15 mph, slapped it in first and punched it and the darn thing started going sideways on me...... I was like whoa man, lol that was with everything stock excpt for the RV cam, carb adapet, 750 edelbrock carb. I didn't have any spark knock issues till I decked the block and heads, then installed the flat top TRW's..... should have kept the dished pistons I guess.

fordchero73

I have a 400 with 351 heads. I had to use spacer in between the heads and intake due to the deck height of the 400. I never port matched the spacers to the heads and intake, but there was not a big difference. This swap meant I could use a 351 Cleveland intake, because there were no intake options for the 400 at that time. I rebuilt the engine and with the new pistons took the compression up to about 10:1. One thing I like about this engine is the dry intake.

The engine runs great, there is enough torque to rip up tires.

I would like to have a 460 one of these days, but this build fit my budget at the time.

mitchalvin

The biggest problem with the 351M/400 was the timming set, it was retarded supposedly for emission purposes. If you put an aftermarket straight up timing set in them you will gain both power and fuel economy. The latter 460 have the same retarded timming set and will gain by using the 429 timming set or an adjustable timming set.

hotrod351

well the breathing, the cleveland heads, 2 barrel heads, have 2.05 intakes which are bigger than the windsor, 4 barrel are, i believe 2.19 intakes.

svt tech

I hate to tell you but 2.19 is bigger than 2.05. If I am not mistaken, the largest intake valve offered on the Windsor engine is 1.85. 2.19 will not fit in the valve arrangement due to the inline design of the windsor engine. Both the Cleveland and Modified engines use canted valves and that allows larger intake and exhaust valves.

hotrod351

gee i thought thats what i said. cleveland 2 barrel heads have 2.05 and 4 barrel cleveland heads have 2.19 intakes. the 2 barrel clcveland heads have a bigger valve than you could put in a windsor and thats just the 2 barrel heads. thats why a cleveland is much better, thats what i have in my 55 f-100. enough said. but thanks for trying to point out, what you thought, was a mistake on my part. these forums need more kids like you to keep everyone on the right track.

Lsballa

I am currently rebuilding a 351m i have pictures if you would like to see them check out some of my threads.

https://www.f150forum.com/f13/1978-f150-smokes-8167/


A good identifier is that the no water/radiator does not go into the intake it goes directly into the block.

Hope i can help.

hanajamin

whats up, I got a 351 M and just found out that the 351C has a c4 trans and the distencs between the top two bell housing is 5.1 inches. On the 351M,because it has more torque from the 400 stroke( hence its title 351M/400), ford had to put a c6 transmission. the distencs between the bellhousing bolts(top two) is quite more, aprox. 1.5-2inches. In the long run now ford can use the 351M in bigger trucks,yet save on efficincy with out using a bigger engin, because now you have more torque.

svt tech

First off. The 351 does not have the 400 stroke. That would make a bore of 4 inches and a stroke of 4 inches producing 400 cubic inches. The designation on the valve cover is 351/400. It is a 400 block hence the wider spacing on the tranny bolt patern. It was "modified" with the 351 windsor crank designating it a 351m. The stroke of the 351w is 3.5. I am not 100 percent sure where the engine was assembled. The 460 was assembled at the Lima assembly plant. The 351 windsor was in Windsor, Canada. The 351 C was also assembled in lima. Some of you true die harders correct m on this if I am wrong. I am quoting off the top of my head. The 302 was also from Cleveland. Hope this is helpful.