70 swinger 360
A CUSTOM STYLE THAT NEVER WAS
I have a 70 Swinger 340 4 speed car, bought it off EBAY 9 years ago. The block number is 53020006-380 and casting date is: 2-24-93. Is it a early Magnum short block by numbers? i wonder if it is a early version with drilled passages in #2 & #4 cam journals that i have read about. The motor has a Lopy cam that makes 7 Inches of vacuum so i use a cycling pump to serve power brakes. All the info i have gathered is that it is a 380 HP 292 duration and .500 lift cam that was used however it is using a flat tappet cam and early LA heads?. It uses the rocker shafts and old style push rods and all is oiling quite well 60 Psi oil pressure at highway and over 40 at hot idle. There are no markings on the outside of heads between spark plugs as i am used to seeing with the old 340's( X J U ) markings. I am going to pull the right valve cover to see if i can get some casting numbers. When I first got the car it had the M1 intake and a BIG holley that i disposed of and am using a stock cast iron 340 manifold and AVS 4933s. I want to use the new edelbrock RPM air gap intake and 750 carb W/ electric choke to help cure the crossover passage hot restart vapor lock and to restore more lower end power. The car has 3:23 gears and is reving 3,000 at 75 MPH, it's nuts on the highway. The question is: It appears to be a early Mag short block yet with flat tappet Hyd cam not roller and with earlier LA heads, is this one of those rare blocks factory drilled to work either way or was machine shop drilled?
