You are looking at a factory Chevy Holley carburetor. I got it in a box the way you see it in an old carb shop cleanout. It is missing parts. It is a model # 4150. ID stamp reads 3972123 LIST 4489-1 021.  List 4489-1 is correct for 70 Camaro Z/28 with 350 / 360 HP LT1 and TH400 auto trans and 370HP Corvette with TH400. Date 021 is the 1st^h week of Feb, 1970 for the 70 model year. The center float bowls are 34R4652-B. The primary metering block is missing. The secondary is 6333. The main body looks ok. The base plate is 12R1856B. The base plate does have some snapped screws in the venturies. Comes as shown.