Cast crankshaft and connecting rods for racing

Stock class? I thrashed on my stock 304 running max RPMs (4600 to 4700) limited by stock valve springs. Only ate on valve on a max rpm blip / shut down. Never had a problem, after changing my head only. If changing to solid lifter or roller cam, then be careful and have it balanced and yada, yada, yada. I would not push beyond 6500 for long term racing use on cast rods. Buick and AMC have some good stuff in their basic v8 blocks. Key is getting the work done for race perposes. Mild porting, Chevy 305 valves, should being some good results without spending extra for whatcha got. Though cost wise, it is cheaper to go to a 360, as it weighs the same and allows for more effective power with a little extra cost, mostly in obtaining an engine.

Mine was a stock engine, with dual exhaust, Holley 650 spread bore with some mods for 304 engine drivability, which were smaller jets, higher plenum (used 1" ported spacer) an Offy spread bore 360 (rare to find these days). Engine was factory rated at 150hp. I assume I got 220 out of it. Though I changed to a Mopar 8-3/4" rear out of a Cornet 500 with 2.76 gears, for highway cruising speeds. Topped out above 138MPH. A Ford Probe GT has a factory speed limit at 138MPH could not pass me as my RPM was maxed at 4700 in drive. Oh I did have a cowl hood, no rear spoiler. Cowl hood added, extra aero, and nose stability. Never floated at any speed. Very stable, considering I used factory 14" X rally wheels with G60 tires.

Edited by 304-dude - Feb/23/2020 at 7:16pm

74jmill_jav wrote: What’s the deal with Chevy valves? Why are they better than the stock amc?

If your racing, for higher than stock rpm use, the 305 valves are a wee larger, for better breathing. A cam and lifter set, will require the head work done. Also if you go with a hugh lift cam, if your heads, have bridged rocker arms, you will need to run LS rockers on machined pedistals, or obtain early 304 heads (70 - 72) with stud mounted rockers.

Ok- so I bought a new “Sealed Power” performance cam for the 304. It came with new lifters and rods. Should I just buy the Chevy 305 valves, or get the stock ones polished? It sounds like the Chevy ones might be the way to go... any suggestions on what exactly to buy since I have no clue the compatibility differences between my 1974 304, and a Chevy?

The Chevy valves is an old engine trick, as the Chevy valves are one once lighter then the AMC valve , so you get one pound off your valve train. The Chevy valves are also cheaper and easier to get. LRDaum