Join Date: Nov 2008
Location: Beautiful Chester County, PA
As you said they look identical and they also share a lot of parts with each other. The only other way I know by looking at the engine is on the Block.
Right behind the Driver Side Cylinder head and toward the firewall, there are numbers embossed on the block. Near the top where the bellhousing attaches you will either see a "5.7" for the LT1 or a "4300" for the L99 or 4.3 Litre engine.
'95 Caprice SS conversion - Bonny Buckets - 96 Column, Shifter and Console - 3.73 Gear and Herter tune - Z/28 Cluster - Blazer OH Console - Green/Pink bushings - Chromed Impala Wheels - Eibach Springs and Bilstein Shocks - Corvette Engine Dress - the list goes on and still more to do...it never ends.