The Stovebolt Site Forums The Shop Area Engine Shop 235 rebuild with 261 cam and lifters

I am in the proces of rebuilding my 235.
I have a 62 block with a 55 head.
Are all the heads the same or shall I go for a 62 head?
Somebody told me to use 261 solid lifters and a 261 cam for better performance - Is that true?
What should be done to the block?
Can I just replace the valves, springs, piston rings and head gasket or should I do more and what?
Shall I convert to a full pressure oil system? The stock bypass seems to work fine.

My truck is a daily driver - I don't want to go with dual carb intake and dual headers right now.
Just want the best performance with what I have.
But would replace the entire top.

Any tips are greatly appreciated, since this is my first rebuild.

Since you are rebuilding the engine, do it right or you will be sorry later. Have the block boiled and tested for cracks. Bore the cylinders. New cam bearings, main & rod bearings. Grind the crank. New pistons and rings. If you can come up with the scratch, have the crank and pistons balanced. Convert the block to full flow filter. New cam and lifters, call Patricks about them. I know the vette used a 261 cam, don't know about the lifters.

For the head, the 848 head is probably the best due to its higher compression ratio. Have it magnafluxed or pressure tested. New valve springs and keepers. Have the machining done for hardened valve seats and umbrella style valve seals.

You really need a split exhaust and more intake anc carb to take advantage of the cam, but they can be added later.

'55 to '62 235 heads were all the same. I like to keep engines as close to original [ as the GM engineers designed them ] as possible. I would use 235 parts made for the 235. I am sure some 261 parts are interchangable but that leaves a lot of room for error, not only in the parts themselves but the parts man who looks up the parts in his magic book.

55 to 62 heads may interchange but I don't believe the 55 is a 848 head. 848 is slightly higher compresion and I would go with it. I would go with a new cam, Patrick is a good source for info and a cam. I think the vette, the 261 and Patricks "mild" cam are all pretty close. Solids are less troublesome but a little noisier.

The cam everyone is talking about is the HOWARD M4F solid lifter cam. Very nice cam, and if adjusted correctly you will not hear the lifters. You can purchase from Particks. I set up the cam 4 degrees advance. and the intake and exhaust .006 & .013 (snug) cold and you can't hear the lifters. Plenty of power you will ever need for a street engine. This cam as the previous post said is correct it's specks are very close to the 261 engine cam that was also used in the 6 cyl vet engine. Good luck.
tim

Thanks for all the very useful advice. It's very appreciated.
I can get a '61 NOS 261 head complete with rockers, valves and springs. The casting# is 3836850. The 850 is probably the 261 version of a 848 235 head.
Anybody knows if that will work?
Will I need a different push rod length with the 261 head?
I am thinking of installing hardened valve seats, although the stock ones are unused (but not OK with unleaded fuel).
I don't want to keep using the lead-substitue - not sure if it ever really helped.
I will do all the necessary work on the block and I will definetly go with Patricks cam and lifters.
His ring & pinion rearend set has made the greates difference so far on my daily driver.

The 261 is the lower compresion head, as I beleive the '55 is. Good choice if you use a blower or turbo but not prefered for normal aspirated engine. I would find a 848 head and have it checked for cracks, put in hardend seats and perhaps oversize valves also available from Patrick's