First question,,,, I have a 2468130 block (383) with 5-25-71 build date. stock bore, mildly built. Four speed. I always seemed to have a vibration in it. My thoughts came to light yesterday when the Harmonic balance came apart and began rubbing against the timing cover. I removed the balancer and it is a cast crank balancer. I also discovered that my engine has a cast crank,,, I actually scoped up through the drain plug to verify this. More research indicated that Mopar did put cast cranks in 2 barrel 383s' in 71-72. The part number for the balancer is 3577180. A two year only item. The 400 cast cranks used a different number. I have not had much luck in finding one on the net.... Second Question, This 383 two barrel engine was undoubtedly first equipped with an automatic trans. I now have a four speed behind it. Would the flywheel have to be balanced with the engine? Did the flywheel out of balance cause the balancer to come apart? I know For a fact that the balance was OK when I got the engine. The cast number on the f-wheel is 8015,,,,, Thanks, Ed
Sounds like the balancer has been bad for a while. Put a new balancer on it and see how it acts then go from there.
Someone would probably give you a forged crank. Certainly not expensive. But more expensive than a balancer.
The cast crank 383's and 400's use the same flywheel and torque converter offset balance. This leads me to believe that the 383 and 400 damper should interchange (though I have not been able to verify this). The flywheel must be balance to the cast crank 383. Below is how the old Direct Connection book shows how to balance a flywheel for the 383, 400 & 440 cast crank engines The same flywheel offset is used for all three engines. The drawing is showing the engine side of the flywheel.
1) Use a neutral balancer and flywheel and re-balance the engine 2) Balance the flywheel (per above), then look forever for the correct balancer. (Damper Doctor in CommieFornia can rebuild it for you) 3) Get a steel crank, neutral balancer and flywheel, and still balance the rotating assy.
What about this one https://www.cnc-motorsports.com/sca8013-scat-harmonic-balancer-chrysler-383-400-413-426-440.html
Thanks guys, Here is what I "think"? The HB for the 71-72 cast cranks 383's had the one offset pulley bolt hole. In 73 when the 400's came out the holes were then drilled equal and a new part number was required.???? SOOOO same balancer on either cast crank engine,,,,, I can not see the three drilled balance spots in the flywheel, so I'm betting that is my problem. I need to remove my flywheel and drill those spots. ORRR get the correct flywheel, Brewers offers the flywheel neutral or balanced (drilled) Brewer's Performance - Mopar A833 4-Speed Transmission and Component Specialists
The other thing to consider, if you haven't already, is the pilot hole in the crank. There are other threads here that discuss the pilot issue.
Yeah I have thought about that too. The moron who cobbled this engine together did something to get the 4 speed in, I will not know what he did till I get the trans out and take a look!!!,,,Ed
