the date code you provided is july 29 1966 (6H29). you have an early 67 engine. it is probably just a standard 428 but if it has big bolt rods and a huge harmonic balancer it could be a PI engine but it is unlikely. and yes the 1U crank was used an all 428's until november of 68 when a revision was made to the CJ's. all CJ's built between 11/67 and 11/68 will have the 1U. hawkrod
Hawkrod
39 Ford Deluxe Coupe
59 Tbird 430
60 Lincoln Premier
(2)62 Tbirds
(3)68 Cougar XR7-G's
69 Cougar 428CJ 4 speed
77 1/2 Ford F250 4X4 w/460 swap
86 SVO mustang
look at my cars past and present at superford! 