[Mr70]

Sure.
Look in box #46 on the buildsheet for this designation.
BQ-part #3019204 w/Manual Trans.
BR-part #3029205 w/Auto Trans.
These were the standard 3 core radiators for the LS-5 & LS-6 Chevelle.

PA-part #3016678 w/Manual Trans.
PD-part #3017248 w/Auto Trans.
These 2 were automatically included if the LS-6 Chevelle had the optional 4:10 rearend ordered,or if not 4:10 equipped,customer ordered the optional Heavy Duty cooling,RPO V-01...These same two 4 core radiators & codes were also used on the L-34,LS-5,L-78 Chevelle/Elco when either Air Conditioning,RPO C-60,or Heavy Duty Cooling,RPO V-01,was ordered.