DO THE CHEVY BOOKS TELL WHAT YEAR BABBIT BEARINGS WERE CHANGED OVER OR STOPED, AND STARTED USING INSERT BEARING'S ON MAIN/CAM'S

The first year to have a replacable cam bearing was the 33 & 34 and it was used in the center bearing only. The 36 had the rear bearing replacable.All later engines hAD ALL REPLACABLE bearings.

As previously stated the 48 had precision main bearing inserts which meant that one bearing could be replaced if necessary. they also used thiner babbit material and the bearings were less likely to need adjusting.Also at this time Chevrolet made the precision bearings available for all 6 cyl. engines as a replacement. They had to be installed in complete sets and then it was no longer necessary to line bore the main bearings when they were replaced. 1953 Power Glide engines were the first to use conn. rod bearing inserts as well as full pressure oiling.All 1954 engines were updated to this system.

Most Chevy engines have had insert main bearings. Possibly the earliest (1913-1915) might have had poured mains. I also vaguely remember that one later engine also had poured mains but it escapes me which one.
Rods were poured or spun cast babbitt until the '53 PG.

I think that all the 216,s were a splash and splater..The full preasure came with the power glyde in 50 I think if you look at an org car look at the oil gauge if is a 60# gauge it came with a full preasure engine the dippers had a 30# gauge..A216 tappet cover goes to the valve cover,a 235 tappet cover goes stops at the head gasket...doc

Correction on the change to inserts and full pressure lubrication. The first Chevrolet engine with pressure thru the crankshaft to rods and inserted rod bearings was the 1953 Powerglide engine, the 235 powerglide engines thru the 1952 model year were babbit rod engines ( with hydralic valve lifters)

MrMack...I think that you are right I have a 50 PG and raised the hood today and it has a shrt tappet cover and a 30# oil gauge...doc

I reciently replaced the mains on my '40 , they were/are inserts . The rods were originally poured and are now inserts also .

New Zealand,,is that south of Des Moines,,where in the world did you get a 40 Chevy 1/2 ton I have been looking for one in and around Iowa and cannot find one I have a 40 dr..How do you get parts to restore and are they pricy...l.l.

Hey doc , yep the '40 is very rare here , in fact , in 28 years this is the only one I've seen here .
Plenty of 37 - 39 pickups , but during the ww2 period all vehicles were taken for use by the military . This truck survived 'cause it was on a high country station ( farm ) and was deemed essential industry etc . they had it till 1974 .
Life is kind occasionally .
parts ?? yep got plenty of worn out parts .
Buying from the States is easy ,, paying for it is not ,, exchange rate is a killer . .