My 99.9% stock 340's would run 14 flat go 165 and get about 20 mpg on snow tires with no posi. no o.d. Stock exhaust system. I have plenty of witnesses. There may be some better stuff out there but it always worked for me. Now add 1.6 rockers, 11.0 to 1, o.d. 4.10's headers etc. what would you get today. Add a high-pressure fuel system. Wow just imagine what you'd get out of that little 340 with a 55 year old cam. O, with 55 year old heads to boot. Now ...