Engine Guru's HELP - The 1947 - Present Chevrolet & GMC Truck Message Board Network

jostrans68 · 05-16-2004, 08:18 PM

I have a interesting dilemma I pulled apart a 350 that had a great crank in it had the block bored and I just polished the crank. The mains had 30 on them and the new 30 over bearings fit great . the thing is the rod bearings had no marking so I assumed that they were standard( i know what assume does) but they are not and of course the crank is now in block. This block was unmolested so it apparently came from the factory like this. The Numbers on bearing are 7555 cap DAB looks to be brand? Is there a way to tell by this old number the size? I tried a .30 but its too tight. I dont want to pull the crank if at all possible thanks in advance Jack

Jeepster376 · 05-16-2004, 08:48 PM

I don't know what those bearings are, but if you get a plasti guage kit and take a reading with the standard bearing, you'll be able to tell which size bearing you need.

Bowtie67 · 05-16-2004, 08:56 PM

30 over is quite abit on a crank, most guys dont like going over .020, usually when you find something this immense you will generally find the rods have also been turned, check remaining rod bearings or take them down to a good autoparts store and they may be able to distinguish if they are stock or oversized from the part number.

jamesi20 · 05-16-2004, 08:57 PM

do you have any machinist or tool maker freinds? you can't beat micrometers for checking these things out.

Stroker · 05-16-2004, 09:18 PM

I think a measurement is probably the best and quickest way to see what you have. You could get close enough to tell if it is standard, 010, 020, or 030 using an inexpensive $10-15 pair or calipers, just be sure to double check with plastic gauge or good mic to determine your final bearing cleance. You might take a look at this link, maybe they have the info you need. Looks like they took over DAB in the mid 80's.
http://www.nationjob.com/company/glda

jostrans68 · 05-16-2004, 10:32 PM

Yea I went down and picked up some plastiguage and will do it tommorow just curious have done a lot of engines and this is the 1st that I saw this on. I am a parts guy and I couldnt find any references to this old number but as usual you guys ae alot of help thanks....Jack

05-16-2004, 08:18 PM	#1
jostrans68 Jostrans68 Join Date: Mar 2001 Location: Bloomington indiana Posts: 1,182	Engine Guru's HELP I have a interesting dilemma I pulled apart a 350 that had a great crank in it had the block bored and I just polished the crank. The mains had 30 on them and the new 30 over bearings fit great . the thing is the rod bearings had no marking so I assumed that they were standard( i know what assume does) but they are not and of course the crank is now in block. This block was unmolested so it apparently came from the factory like this. The Numbers on bearing are 7555 cap DAB looks to be brand? Is there a way to tell by this old number the size? I tried a .30 but its too tight. I dont want to pull the crank if at all possible thanks in advance Jack __________________ [CGTW Member former 67-72 now with a 96 silverado

05-16-2004, 08:48 PM	#2
Jeepster376 Registered User Join Date: Feb 2004 Location: Massachusetts Posts: 269	I don't know what those bearings are, but if you get a plasti guage kit and take a reading with the standard bearing, you'll be able to tell which size bearing you need. __________________ 72 Cheyenne Super 4x4 SWB

05-16-2004, 08:56 PM	#3
Bowtie67 Registered User Join Date: Jan 2004 Location: NH Posts: 2,266	30 over is quite abit on a crank, most guys dont like going over .020, usually when you find something this immense you will generally find the rods have also been turned, check remaining rod bearings or take them down to a good autoparts store and they may be able to distinguish if they are stock or oversized from the part number. __________________ 1967 C10 - SWBSS Pro Street 427sbc, 700R4 & 4.10 Gears 1948 Chevy FleetMaster Coupe, LS1, (almost done) 1950 Chevy StyleLine Coupe 250/6 3x2 Dueces 2009 Toyota Tundra 1996 Harley RoadKing "I maybe getting old, but I can still burn rubber with the best of them"

05-16-2004, 09:18 PM	#5
Stroker Registered User Join Date: Mar 2001 Location: Moore, Ok Posts: 1,149	I think a measurement is probably the best and quickest way to see what you have. You could get close enough to tell if it is standard, 010, 020, or 030 using an inexpensive $10-15 pair or calipers, just be sure to double check with plastic gauge or good mic to determine your final bearing cleance. You might take a look at this link, maybe they have the info you need. Looks like they took over DAB in the mid 80's. http://www.nationjob.com/company/glda __________________ 72 SWB parts and pieces Oklahoma

05-16-2004, 10:32 PM	#6
jostrans68 Jostrans68 Join Date: Mar 2001 Location: Bloomington indiana Posts: 1,182	Yea I went down and picked up some plastiguage and will do it tommorow just curious have done a lot of engines and this is the 1st that I saw this on. I am a parts guy and I couldnt find any references to this old number but as usual you guys ae alot of help thanks....Jack __________________ [CGTW Member former 67-72 now with a 96 silverado

05-16-2004, 08:57 PM	#4
jamesi20 Senior Member Join Date: May 2002 Location: NORTHEAST OHIO Posts: 494	do you have any machinist or tool maker freinds? you can't beat micrometers for checking these things out.



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