World Products has redesigned the famed Merlin Big block Chevy casting, incorporating numerous improvements and new features. Designated the Merlin IV, this new block is sure to be a favorite among racers and professional engine builders.
New features include thicker min webs for increased strength cylinder walls which are nominally .310" @ 4.600". The oil system is revised with enlarged passages and cross overs in front, uses simple pipe plug type restrictors, .500" oil gallery is relocated so 55mm cam does not require lifter bushings. The block will accept cam journals up to 2.480" or 60mm Babbit and 1.060" lifter bores. Also new are deck heights from 9.500" to 9.850" and 10.200" to 10.250".