If its a true pontiac 261 then the block is drilled for hydraulic lifters. That means you have your choice of using hydraulic lifters or solid lifters. If you want the motor to be quieter, then order a hydraulic grind cam and dig up some nos gm lifters. A 55-58 block, use 55-58 GM 235 hydraulic lifters, and a 59-62 block uses a slightly different lifter so use the 59-62 GM 235 hydraulic lifter. These lifters can be a little bit of a bear to find so be patient but real GM, or aftermarket nos that are at least 30 years on the shelf. If you decide to use mechanical solid lifters, use the solid lifters from a 56-62 261 truck. Do not use the milk bottle style lifters, they are a different design, for a different cam and cam material and an earlier motor (54-early 55). Also, you have to have the cam ground for mechanical lifter use. The cam lobe design is different depending on the lifter so you want to use a cam made for the type of lifter you will be using.
Last edited by Dragsix; 11/17/2020 3:49 PM.
