I am looking at buying a 4l80e for my classic and the junkyards are asking me if I need a mcp or a mjp model . Does anybody know the difference?

 

I don't know the difference with the letters but early ones have the cooling lines up front like the th350 and the later ones they have one up front and 1 in the rear towards the tail shaft.

 

I cant find a real answer I have seen some say the yoke are different they think some say its a wheelbase difference they think but no real positive answer. Junkyards don't seem to know, the transmission shop by my house said ask junkyard and the junkyard said ask a trans shop. I just would like to know the real difference so I buy the right one. I am looking at a 4l80e out of a 2000 gmc single cab truck and there is two options mcp or mjp. Thanks for the info I will check the trans line location.

 

So I was told by a guy that rebuilds 4l80e transmissions that the difference between mcp and mjp is calibration in valve body. There was a mid year change in 2000 and they used mcp and mjp to tell the two apart both will work they will just shift differently he said most people don't notice the difference. same size same yoke, the computer will work with both. In 2001 they all came with mjp code. So this information is for the guy replacing his 2000 4l80e and when asked which model you have now you know the difference.

 

Ok I've got a 2000 C3500 with the newer style 4L80e transmission, it has the Cooler lines separated one in front one near the rear , it has the longer linkage shaft sticking out for the nuetral safety switch mounting in side of trans my question is , only cause I was given a built 4L80E never even installed but it it older style with both cooler lines together up front , it has the little stub sticking out for linkage which I'm assuming is to short to get the switch andi lnkage onto , I've been told do many things as to reasons I can't use the old one that was given to me ,is there a kit to. Make a 2000 C3500 accept the old style ? From what I gather the shaft would be to short the cooler line will be to long , is the connector the same ? And what about the speed sensors . ,This is an old At&t telephone truck with almost 300,000 miles on it with a utility bed and ladder rack it weighs around 12,000 lbs loaded with my tools and I do pull a trailer often up and down steep hills almost every night . It has the 5.7 vortec

 

I thought the ones with the line front and the line to the rear, had better lubrication...??