School Me on Big Block Hyd. Lifters

[Ramman]

Some vendors list hyd. flat tappet cam kits, for RB engines, with lifters only fitting 68 and later blocks. What changed? Lifters? Blocks? Both?

[RUNCHARGER]

The block, heads and overall length of the lifter and pushrod package was the same. The 67 engines used lifters that had the pushrod cup at a different height than 68 and later engines. So the pushrod length and lifters were different when changing 1 of those items where everything is stock and original in a 67.