Roller lifters?

[SMS]

Anyone know how to tell if my 4.3 is a roller cam or not? Its a 93 S15 with TBI. I am looking to put a mild cam in it and possibly roller rockers. I want to improve torque for towing. Any input would help.

[poconojoe]

87 and newer should be roller lifter motors

[Crew Cab Sonoma]

also keep in mind, the cams are not interchangeable between balance shaft equipped, and non-balance shaft engines.

some of the TBI equipped 4.3`s had balance shafts, and some didnt in those years.

[fastr68]

just because its an 87 or later doesnt mean that it is definitely roller equipped

some were not

i have seen and owned and been inside of many 87 up that were still the old flat tappet design

good luck

[Crew Cab Sonoma]

Quote: Originally Posted by fastr68

just because its an 87 or later doesnt mean that it is definitely roller equipped

some were not

i have seen and owned and been inside of many 87 up that were still the old flat tappet design

good luck

i`ve been into plenty of 87 model Chevy 4.3`s, 305/350 engines, and havent seen one that didnt have a roller in it...

i have seen several 86 SBC`s in various stages of factory casting and machining prep for the switch to rollers.

[poconojoe]

Quote: Originally Posted by fastr68

just because its an 87 or later doesnt mean that it is definitely roller equipped

some were not

i have seen and owned and been inside of many 87 up that were still the old flat tappet design

good luck

You better tell GM

BLOCKS
1985: The original block in ’85 was a 14071177 casting. It had a two-piece rear seal, a flat tappet cam and a fuel pump hole because all of the trucks still had carburetors. Just for the record, there were some ’86 blocks shipped with pans for ’85 service replacements, so it is possible for a customer to have an ’85 car or truck with a one-piece rear seal.

1986: In 1986, the block (c/n 14088553) was modified to accommodate the new one-piece rear main seal. The fuel pump hole was still open, even though it wasn’t always needed, because all of the cars and some of the trucks came with throttle body injection.

1987- ’94 WITHOUT BALANCE SHAFT: In 1987, a roller lifter cam was installed, so the block was changed again. Two bolt bosses were added in the middle of the valley for the lifter retainer that kept the rollers properly located on the cam and perpendicular to it. This same basic block was used through ’91 for everything, and in ’92 through ’94 for all of the engines without balance shafts except for one small difference – some of the blocks came with four bolt holes for the tunnel style retainer beginning in ’92. There were several different castings used, including the 10105867, 10172756, 14099073, 14093683 and 10066011 with the two-bolt retainer, and the 10172756, 14099073 and 10066061 blocks with the four-bolt retainer.

1992 WITH BALANCE SHAFT: The L35 balance shaft engine was introduced in ’92, so the block was modified to make room for it above the camshaft. The lifter retainer was changed to the tunnel design because of the balance shaft; it had two bolts on each side instead of the two in the middle.

[Crew Cab Sonoma]

edit: double post.