My records show the heads as being from 327 210hp from 1962-1967, car or truck 1.72/1.5 valves. This is exactly what heads you'll find on a standard 210hp 327 in most Chevys of that period. There were 74.7cc heads used on '57-67 283 trucks but these were 3774684 heads, and the engines would be below 8:1 compression.
I'll find out for you about the single digit year code. It was applicable around '63 but I think it stopped by the later 60's and Tonawanda was the same by then. If yours doesn't have the T it will be cast at the Saginaw foundry.
I just looked up the 1967 GM Engineering specs for Trucks. There were 4 x truck 327 engines for 1967:
L30 275hp 10.5:1 (El Camino only) - flat tops with fuellie 64cc heads.
L79 325hp 11:1 (El Camino only) - lumpy tops with fuellie 64cc heads.
L30 High Torque 220hp 8.5:1, C10-C30 and K10-K20 - flat tops, 4BBL with 75cc heads.
L30 High Torque 185hp 8.0:1, C50-C60 - dish top pistons with 75cc heads.
The high torque engines have premium bearings, special cobalt-based alloy collating on the exhaust valves with rotators on the exhaust valves, forged steel crankshaft. All the engines share the same General Performance camshaft, same cam we got in GTS327 and GTS350. The water pumps used on the high torque 327's were higher flow 75gal/min @4000rpm vs the standard 57gal/min @4400rpm.
This engine may be the High Torque L30 220hp engine.
Edited by user Thursday, 10 December 2015 9:53:24 AM(UTC)
| Reason: Not specified