VCCA Home Forums TECHNICAL - GENERAL Trucks and Vans 261 engine questions

I bought a 261 engine out of a 2 ton truck (I believe it is a 1958 are they all the same)? I believe it has a solid lifter cam in it now, can a hydralic cam be installed from a 235? Do these engines 235 & 261 oil the same? Are they basicly the same engines only larger bore, stroke, valves etc. Thanks Ross

If it is a 1954-57 261 engine there will be no oiling for the hyd, lifters.The 1950-57 235 with hyd. lifters fed oil from the rear cam bearing to the passage in the block that went from lifter to lifter.The block was drilled (from the rear) from lifter bore to lifter bore, right up to the front lifter.Solid lifter engines did not have this "feature"....
In 1958 the oiling system was changed.All engines had the lifter bores drilled.The oil was fed from both the rear cam bearing and the front cam bearing.In the center the oil passage to the rocker arms tapped in and it ws fed to the rockers via a passage in the block and head.The solid lifter engines used a different lifter .It was cut down in the center like a hydralic so the oil could pass around each lifter.This engine would have no oil line behind the push rod cover...the 1940-57 has the line from the lower rear corner to the center upper area-this is the rocker arm feed.
With the above info. I see no reason that the later 261 could not run hyd. lifters.All the lifters need is to be suronded by oil, from there they will pump themselves up buy the up and down movement of the lifters inner pistion (with engine running).
All 261's came with a higher lift camshaft (also used in some 235 trucks).The larger displacement engine can use the extra valve lift OK.A good choice would be the 1954-58 Power Glide and 1956-58 passenger car std. transmission camshaft.It was about equal in lift to what the 261 used.Important to use the 261 valve train or the valve train from the high lift cam engines I mentioned as the rocker arms were stronger as were the valve spring.
The 261 used the same sized valves-only a better quality for longer life.The head was the same except for the steam holes, manifolds the same but the carburetor had a slightly larger throat.

Thanks Gene for your help. Ross

Ross, see your from Maple Park, got a friend I worked with for 25 years lives there, Kenny Schultz. I'm just down the street in Sandwich.
I just picked up a '50, 3/4 ton that I am in the process of restoring, if you would like to communicate heres my Email; dgraham@indianvalley.com

I had a couple of 261's back in the 60's in a '60 Biscayne, good engine. I was a partsman for Chevrolet out in the suburbs at the time and don't remember ever having a problem with them.
Gene sounds like he knows his stuff, I'd take his advise.
Denny Graham
Sandwich, IL