351m to 390 going Hi-Pro

I have a 81 F150 4x4 with a 351m 4sp changing it for a 390 and c6 tranny. Want to get as much HP as possible where is a good place to find HP parts? Block is going to go 30 over.My little lady wants a fast 4x4.

Why not rebuild the 351m as a 400. All you need is a 400 crank and pistons. CHeck the link below for a 385 hp 400 buildup

http://www.geocities.com/styleline58/400.html
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the 390 will make gobs of torgue,but the change requires new frame to motor mount brackets,also keep in mind that the rear motor mount[trans mount]stays constant,all of the drive line,shafts,clutch,and linkages stay lined up,no matter what you put in,i agree to rebuild the m series,use later heads with hardened seats,some trick stainless valves,just watch the lift of the cam,and coil bind,the [FE] passenger,light truck had no hardened seats,if you do put a 390 in,have the exhaust cut for 428 cj specs,will not lose bottom end,and use STAINLESS valves,then you have a set of very close 406 heads,202 ins,from 156,to 165 on the exh,also USE HEADERS!,MAKE sure THE EXH PORTS ARE RIGHT,there is a 1/2 in dif in the ports,not the bolt pattern,i also found the crane power max 260 cam[fe]whips up some bottom,andVERY STRONG MID RANGE,I BEEN RUNNING IT FOR YEARS,CAN LITE UP 36" TIRESalso break axles on shifts,also on the [fe] check head to intake match,large port heads can use small,or large hole manifolds,small port heads cannot use large port intakes

If I had an M, I'd replace it with a 429 or 460. Bolts right to the tranny, and stock mounts are in the wrecking yards.

If you already have a strong running 390 then I would think about it. If you are starting from scratch the FE's are probably not the way to go. You could do a strong running 400 pretty easy as said before or if you fill like you need to be different a 460 would be easier and cheaper to do and gives you way more room to grow.

Go for the 390, i ran one in my 65 for a good while, tons os power. I suggest the Edelbrock heads. I put a set on mine and it was a completly differnet motor. Depending on wich cam you put in it you will need an adjustable valve train[img]/phpBB/images/smiles/icon_tup.gif[/img]