Farmall Cub

I am getting ready to finish the M Project. However I am not sure which pistons to get.
It is a distillate but am not intending on burning K1. it has a 45 head on it and seems to have the proper clearances for domes.
What are the advantage/disadvantage . of either/ or.
I need to help deciding today.
Phil

The dome pistons result in higher compression, thus giving more horsepower, and were original equipment on tractors with the "X1" serial number suffix, which designates "high compression, gasoline". If you will be "working" the M, go with the step head pistons. If it will be mostly a parade and show tractor, the choice of pistons really doesn't make any difference, although the lower compression, flat top pistons MIGHT result in easier starting, especially if the battery is a little weak.

The whole idea of distilate was more power cheaper. That said do what you want.

beaconlight wrote:The whole idea of distilate was more power cheaper. That said do what you want.

I know the idea was cheaper, and at the time that was definitely true by a large factor, but old timers I talked to that ran them said they could not tell any increase in power.

Distillate fuel was several cents cheaper than gasoline. That is why it was the main fuel of choice, but it did NOT yield more power, which is why IH offered the optional high compression, gasoline only version, which DID produce slightly more power.

I ordered the dome style They were 60 bucks cheaper than the flat head as a whole. with the thought tat i am not running k1 I figured it would not make much difference, should I run a higher octane or would reg unleaded be OK
Thanks for the input.
Phil

The compression still won't be THAT high. Regular gas will be fine.

Yes, regular unleaded will be just fine. E-10 is what I use in all my tractors.