I have 12 NOS solid lifters in an original GM box. The end of the box that had the part number is missing. The lifters are the new style. (not the milk bottle type). The push rod seat is a solid machined smooth dip in the top with a relief machined in the side. Hand writing on the box indicates they are a two piece; a separation line appears about 1/4” from the bottom. They are the correct diameter; however, they are approximately .0962” shorter than other lifters I have. The short lifter is 2.188 inches tall and other lifters I have are 2.315 inches. (measured with dial caliper) Was there a change in the design over the years? Can this short lifter be used in my 261?[img]http://[/img]
Ignore the overall height of the lifter body. Figure out a way to measure the distance from the bottom of the lifter where it contacts the camshaft to the depression where the pushrod fits. If it's the same, or close on both types, use the same pushrods. If not, acquire some pushrods that compensate for the height difference. There's a company that I linked to in another post that will fabricate new pushrods of any length and end dimensions that you specify.
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
As suggested by Hotrod Lincoln I measured the distance from bottom of lifter to bottom of the pushrod depression. That distance is very close to being the same on both lifters. Question answered, thank you. Different in appearance but function the same.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
As suggested by Hotrod Lincoln I measured the distance from bottom of lifter to bottom of the pushrod depression. That distance is very close to being the same on both lifters. Question answered, thank you. Different in appearance but function the same.
Please note that "very close" is not "the same". I would strongly recommend verifying your combined lifter/pushrod length is correct before running this setup. It doesn't take a lot of error there to kill a pretty hard/expensive to replace cam.
http://www.gmpartswiki.com/getpage?pageid=21163 - Apparently the 1958 Catalog had a typo as the later 1979 Catalog indicates GM# 5231880 is the correct one for ALL 235/261 6 Cyl '56-'62 + '63 w/4WD with the added detail "(2-3/16" long-two piece)".
Hope this is clearer than mud???
Dan
EDIT: The 2-3/16" length measurement specified in the '79 Catalog converts to 2.1875 (within 0.0005 of your original measurement of the "short" lifters).
Last edited by Gdads51; 04/13/20232:01 PM.
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
[quote=No1300]Please note that "very close" is not "the same". I would strongly recommend verifying your combined lifter/pushrod length is correct before running this setup. It doesn't take a lot of error there to kill a pretty hard/expensive to replace cam.
Why is there close to 1/2" of travel available on the rocker arm adjusting screw, then? Getting obsessive/compulsive about an irrelevant manufacturing tolerance is sort of like lying awake at night wondering why the kitchen sink faucet isn't dripping. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Why is there close to 1/2" of travel available on the rocker arm adjusting screw, then? Getting obsessive/compulsive about an irrelevant manufacturing tolerance is sort of like lying awake at night wondering why the kitchen sink faucet isn't dripping. Jerry
Note that I said to verify that the combined length is correct. I did not say it would not work.
I don't know what the old-timey expert way to verfiy that is, but I would do it by ensuring that there is sufficient adjustment in the arms to set it up properly.
Given no actual data on the measurements, I hold by the recommendation to not just assume they are close enough without verifying it.
Then again, I am the guy that measures the new cam and pistons that I got from Summit to make sure they are actually in spec before I install them. Overkill? Usually. But I have found more than one new part to be out of spec before I installed it.
I degree every cam I install to verify that the lobe profile matches the timing card. If it doesn't suit me, I come up with a combination of parts that does. That might include using parts from several manufacturers in the same assembly. I rebuilt an air cooled Volkswagen engine with "big bore" cylinders and pistons using flathead Ford V8 piston rings and Corvair wrist pins, and ran it over 70K miles that way. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
