Short background: I have a Bronco with a 351m that I've been thinking of stroking into a 400.

For those of you that have played in the 400 sphere, especially recently, do you see the 400 aftermarket continuing support for the next several years? I'm probably within a year or two of making an engine decision for the long term on this Bronco. I plan on 35" tires, but other than that, it won't need to do anything crazy. A 400 stroker sounds great because my Bronco is already set up - kind of a drop and go type thing. But finding 400s seems to be a challenge (or I'm looking in the wrong spots), and I'm concerned that the market may dry up as a function of time. I've kicked around a 460 swap, but that seems like a fair amount of fuss. I've got some mechanic skills but limited fab capability, although I do have some friends I can call on here and there.

I know this is a 400 forum, so I'd expect some partiality to the 400. But this forum also has many folks who have built what I'd like to build, so I wanted to see if I could check-step with your opinions on the viability of this platform going forward.

Thanks.

 

The aftermarket for the Ford 335 series will be around for decades... The 400 isn't going to disappear anytime soon.

There are currently only a couple of items NOT readily available for the 400. There aren't any aftermarket blocks or crankshafts available, but Molnar makes connecting rods. There are lots of aftermarket cylinder heads - Trick Flow, Edelbrock, CHI, etc. Lots of valvetrain support from Comp, Crower, Howards, Lunati, etc. I would be really nice to have an Edelbrock Performer Air Gap or a new Holley Street Dominator intake, but at least there is the Edelbrock Performer and Weiand Action Plus intake manifolds.

There are lots of good parts out there and simple fixes for any oiling deficiencies the 335 series has. Build it, enjoy it, and don't worry about it!

 

This is a 335 series engine forum, of which the 351M is member of. Why not build your 351? The 5.8M and the 6.6 are basically the same. Actually I believe they are the same, only the stroke is different. Both need and respond to the same remedies, compression and timing. I guess the 400 will produce a little more based on displacement(3.5 vs 4.00 stroke). They have the same magic as the Boss 302 and 351C(canted valves).

 

There are no decent off the shelf pistons available for a 351M... and nothing close from other engines as they have an unusual compression height... However, TMI sells vastly better pistons than anything that ever came in a 351M or 400 for the 400... There are also stroker cranks available to go bigger than 400 (actually 402") to 421" or larger but very pricey...
https://www.tmeyerinc.com
https://www.summitracing.com/parts/sum-k5201