360 small block info

[howiedodat]

Hello All !! My 360 is, I believe, a 1970 model. When I removed the heads j code and ran the numbers, they came back as a 1970. My dilema is all the sites I have searched dont list a 360 in passenger cars till 1971. I assume that means my motor is a truck motor. No problem, but I am hoping someone can tell if the are both external balance motors. I am doing a tranny install (727) and will be using a B & M flex palte for the neutral balance convertor and for a external balance motor. I had a vibration in high gear and believe the tranny is the cuprit as I was also getting the loss of third gear under hard acceration (motor would rev until throtled back then would pick up third). The out going 727 had the flex plate for a neutral convertor, so I am assuming the set up was proper, but that is my concern. Is a 360 prior to 1971 a external balance motor ? Thanks !!

 

[70aarcuda]

ALL 360s from the factory have cast cranks which are externally balanced.

if the motor had a neutral converter look for the weights on the converter...

if no weights on either...you probably found your vibration...

 

[Locomotion]

360's with a 1970 casting date were manufactured in 1970 for the 1971 model run. That is why they are said to have been introduced in 1971 - the model year. Cars and trucks can also have production dates a few months before their "model" year.

As mentioned, all the 360's were similar until the 360 Magnum was introduced.

 

[green1]

Pull the pulley of the balancer- it will say external balance, if it is. I don't thing you have a 360 from that year.

 

[Locomotion]

Pull the pulley of the balancer- it will say external balance, if it is. I don't thing you have a 360 from that year.

Only cast crank 340's had "USE WITH 340 CAST CRANK ONLY". 360's originally had a wider, heavier counterweight than a 340, but it was blank. Later 360's had weight taken out of the opposite side of the balancer/damper. Also had no message.

 

[Judge Mills]

I COULD be way off, but your balancer could be worn out. My buddy had to replace his on his 360 to get rid of his vibration.....

Just my two cents...

 

[fishy68]

The out going 727 had the flex plate for a neutral convertor, so I am assuming the set up was proper, but that is my concern.

All Mopar factory flex plates are the same design and have no weights welded on them. The weights for an externally balanced Mopar are welded onto the converter itself. Look on the front side of the converter and you should see a balance weight welded there. A neutral balance converter has no weight welded to the front of the converter. Please note all converters have balance weights welded to the outer rim of the converter to balance them neutrally. Don't confuse them with the weights to balance an external engine.

 

[ramcharger]

Fishy is right 100%. I have heard of people grinding the weights off to "convert" a torque converter to neutral balance.......Bad idea.

 

[howiedodat]

Thanks Folks !! MY general concern is that I know I have a neutral convertor and the B&M flex plate for externally balanced 360 so goes the motor, I should be good. Thanks again !!