79 l9000 big cam.

Could be anything including a small cam. It’s a 79 lots can be changed in 46 years

 

Left side of engine block just below the head Gasket for #6 cylinder, get that serial number and call your local Cummins dealer. They should have some information….

 

Yea, just look at mine….

 

I drove a 1979 back in 1980, it was the original BC 1.

 

Yeah I drove a 1980 Peterbilt with a big cam 1- 290 in it so I'm pretty sure that's what it would be

 

If you don’t know if it’s a 1,2, or 3 you got no idea what’s in it

 

I guess what we're saying here if it was original, it would probably be a big cam one but in that many years, it could've been swapped out two or more times and could be anything.

 

Found this online take it FWIW,


Big Cam 1 was basically a small cam but with a block change to fit the larger diameter flanged cam,larger camboxes & rollers plus new pushrods,modified water pump and new bolted conrods.It still had 60psi lube system,log exhaust manifolds,cummins ST50 turbo's,ptd injectors and AFC fuel pump etc.

Big Cam 2 changes were..alloy sump replaced by tin sump,40psi lube system,pulse (extractor) type exhaust manifold,cummins T46 turbo,top stop injectors,flangeless camshaft,block modified to use smaller main bolts (stupid idea!!)

Big Cam 3 and the 86NT modificatioin (best of the lot) were the first to use Holset HT3B turbo's,crossbolt 2 pass aftercoolers,new style twin pass oil cooler with twin filters,improved durability camshaft,small port cylinder heads & pulse manifolds,modified aftercooler water flow and black paint!!

Big Cam 4 (which was originally released as N14) had low flow water cooling system,modified aftercooler,twin thermostats,STC injectors with black box controller,BHT3B holset turbo.