The first 2 heads are the 360 heads. It is stated that they are ported to a 44% increase over stock heads which flow 200 cfm at least if not a tiny bit better. So, at least an addional 88 cfm makes them a pretty good flowing head. 288cfm should be able to get you moving well. Produced before Edelbrock came about?
Each price is per head. (1 head complete.)
All prices are the Racers Net list in the year 2000.
For the P4876179, 2.02-1.60 ported for .500 lift, $1206.60.
For the P4876180. 2.02-1.60, ported for .650 lift, $995.00.
-----------P5249459, 360HP- 1.88-1.60 (1 Stock head complete) $495
-----------P5007089, W2 head assembly, unported, $862
-----------P5007047 STAGE V, 500/505 service head, $867
-----------P5249112 STABE V ported/2.14-1.81 (15% flow increase) $1295
-----------P4876186 Stage VI non CNC ported heads with 2.14-1.81 $1375.
-----------P5876187, Stage VI non CNC ported head, 2.18-1.81, $1935
-----------P4876857, HEMI, $1495. Not ported, just an assembled head.