I have a 77 f150 with. 300 in it 4 wheels drive and it has some blow by and needs cam bearings I was thinking about pulling the head and re doin the head and putting a bigger cam with new bearings and I have heared about these four barrell carb and manfoilds off a Efi and it would help power some I don't have the money for a full rebuild and a machine shop to so I am hoping that I can get away with a new cam and bearings and rod and main bearings the only reason am putting new bearings In the bottom end is I am gonna be right there why not do them in don't smoke or burn oil so I know my rings are ok and good compression what kind of cam do you guys thing will be good I got 411 gears and a 4 speed with granny low so it will be used for mudding and pulling what do guys think I open to options thanks

 

Im not much on building a performance 300 but your right about the efi manifolds. Also use rocker arms for a 260 chevy 6 cyl. They have a higher lift. Ill have to look a bit but a few buddies on another forum have hopped up the cam in their 300. Ill post back when i can find it.

 

My buddies went with a comp 260h cam and lifter kit and a offenhouser intake with a 4bbl. He is still making a load of low end grunt but makes great power to pull a 3200 pound boat up a 6% grade at 1600 rpm in 4th on a granny np435.

 

On a side note yesterday i hauled 1.6 ton of gravel in the bed of a 86 f150 4x4 styleside. Pulled it like it wasnt there. Need to upgrade my brakes if i pull it again but i stand behind my thinking that it would pull a house down.

 

You state that it has good compression so the rings are good in the next sentance you state it has blowby [[rings are bad] if your in it this deep at least inspect and hone the cylinders and install new rings there nothing like a good valve job and compression bump with worn rings to start burning oil and smokeing

 

I was told that blow by was bad valves because blue smoke comes out of the breather on the valve cover but I hope I can hone the cylinders and put rings in it if that's what blow by is I just need a bit of help on blow by and what it is I have built a few motors but they were Chevys 350 and 383s but when I got the blocks and parts the machining was already done

 

Blow by can come from worn rings or worn valve guides, put a vacuum gauge on it and look in a Chilton manual in the tune up section it tells you how to determine what's what.

 

Blow by is combustion gas leaking past the rings into the crankcase. worn valve guides/seals will cause oil consumption and blue smoke out the tail pipe but will have no bearing on blow by gas. a quick check for excess oil in the breather vent that goes into the air cleaner will tell you if its excessive.