i have a 1978 f250 4wd with a 351 modified in it, i want to do some upgrades and from what i was told from the guy i bought it off of, the engine was "rebuilt" by a kid HE bought it off of. so how do i go about this? im not sure how to tell if i have a stock cam and lifters, or the bore stockness (i know thats not a word). im just a little puzzled and would like some guidance please. also my truck is automatic i was wondering if it was possible to swap the auto to a manual with out any problems (asking cause i have a 78 man trans in my garage with all parts to work) figured id pick your brains on these questions.
thanks in advance

 

Tearing the motor apart would really be about the only way to tell. What kind of upgrades are you looking to do to it?

 

well id like to get more hp outta the engine and i figured it was a good idea to upgrade since its a 1978 engine

 

If you want to change to a standard xmsn 1.you will need a different flywheel, you will need a standard one not a auto one. Get a under dash pedal assy, different support cross member for the trans, all associated frame/bell housing brackets for the linkage.

Maybe a different different length rear d/s or at least see it a auto and a standard are the same length? Is the trans going to bolt to your bellhousing, is your xfer case going to bolt up to your trans on the back side.

To me all the work ain't worth the trouble. If you have a similar year parts truck setting right there its not bad.

Otherwise slap on a alum intake, good carb, some fenderwell exit headers and Auto Rock it!

 

hell ye man, thanks for the input. im going to put a 6 inch kyjacker lift on the 78. now i have an edlbrock intake manifold and an edlebrock carb but it looks rugged (has a pull choke that i never used to start it with) and a ****ty looking throttle body spacer(looks like a pice of wood) how should i go about the carb

 

I put the same thing too include the rear springs, on my red truck (ch it out in my garage) its a 351M 4 spd. Edelbrock intake/carb and hedman fenderwell exit headers.

Its not wood, its called phenolic material, good to help prevent heat sink/vapor lock issues. They make a alum one $$, just get 2 new gaskets and use it.

 

ok thanks! wht u do for tires because i also have a 3 inch bodylift waiting to be put in

 

Drive shafts are different lengths because the standard trans is 3" shorter. The trans crossmember and mount are the same. The transfer case mount will need to be moved forward but the holes to do so are already in the frame. You will need the transfer case shift linkage from the standard or shorten the one from the automatic. It's no fun putting the pedals in. The steering column has to come out, the brake booster bolts all have to come out and some of the dash as well. The bolt holes are already in the frame for the Z bar and the clutch rod hole is already in the floor. Make sure you have the piece that holds the clutch spring and know just where it bolts on. It took me 3 nights after work to change mine over.

 

351M is hopeless for any real power.

See the 335 engine series forums for many threads and examples on changing it to a 400. Crank and pistons is what you need, plus cam, manifold, headers, carb, maybe head work if you want to go nuts. Plus, the usual engine rebuild items.....

 

Thanks mark a. for the correct/additional answers. And for the OP I have run 35 and 36's all day with plenty of clearance.

With a 3"body lift, I would say 38's, 39.5 or 40's no problem.......

 

i would not do the body lift. i got the truck with the 3 inch lift and would never get
another truck with one. just replace the stock body bushuings.
i also use a 1 inch phenolic spacer for my edelbrock carb. made a differnce for sure
as far as heat in to the carb.
also check timing chain and gears make sure to use a straight up timing set with a good cam will make some good power.

 

What brand has a good cam/lifter kit

 

77&79F250, did u cange the gears in ur axels? For bigger tires should i? What should I get?

 

i found a comp cam k32-238-4 kit, i found it on summit racing it has

Mechanical flat tappet
Retainers Included
Locks Included
Valve Stem Seals Included
Timing Chain and Gears Included
Double roller Timing Chain Style
Assembly Lubricant Included
BUT...it doesnt have
Pushrods
Rocker Arms
Gaskets
Valve Springs
do i need all these parts, obviously i need a gasket but the push rods, rocker arms, and valve spring?

 

That cam specs 9:1 CR or better.

Your engine now tops out at what, 3500rpm?

Yes, you will need springs at least.