I have a 1979 F150 4x4 With a 351m/400. Vin says 400 PO says 351m idk.

Do these 335 series share trannys with other series (windsor, 385 ect?)

Are these series reliable for daily use and or playing?

I'm considering a motor swap to a motor I am more familure with but if I can save money and this motor series are reliable and tough I'll stick with em.

What are the main killers of these motors?

What kind of power range am I looking at with bolt ons?

 

do your home work,all that info is here if you search. If your engine has the correct factory balancer on the crank, the 351m will be about 1' thick,the 400 will be 1.625, they do interchange so it may have been changed. The 351m/400 is prone to cracking in the lifter valley and the heads, i just went threw 3 sets to find a good pair but, these engines are worth the effort rather then changing to a 460 boat anchor. Good luck with your build.

 

I'll second what Bud said - keep the engine, don't swap. If in doubt of the power potential of these engines just lay a W head next to an M/400 head and note the much larger ports on the latter.

The main issue, beyond the cracking and I've not had a problem with that on my three engines, is low oil pressure at idle. And Tim Meyer has a good and cheap fix for that.

As for sharing transmissions, sorta - they have the same bell housing bolt pattern as the 385 series, meaning 429/460. But, while the bolt patterns are the same the flywheel on the 429/460 is further aft ~1/2". So, while a ZF5 will bolt up it won't work w/o adaptation as the input shaft won't reach the pilot bearing. But, there are ways around that.

 

Thanks for the info guys, I've been a member here for about 6 years and never have been able to get the almighty search function to work for me

 

On the main 335 Series Forum page find Search on the right. Click "thread" or "post", depending on what you need, and enter the topic terms. Like, maybe "crack" or "oil pressure". Hit "search" and you'll get a list of threads/posts that meet the criteria.

 

Thanks bud!