1954 "G" motor piston question.

[tracerbob]

I've got a set of nos cylinders to replace the old cobbled up ones on my 45 servi-car. So, in locating a set of pistons I find they're are two different kinds. Early (253-29A) and late (253-55A). What is the difference between the two and does it matter which set I use? And does a sevi-car use a completely different set?

Thanks
Robert

[Rubone]

The difference in the -29 and -55 pistons is in the width of the rings, the -29 is thicker while the -55 is the new thin type with better oil control rings. Either will fit any 45 application and Servi-Car pistons are the same as all the rest. The compression differences are in the heads.

[tracerbob]

Thanks for the info. I've got one more question. Would a servi-car run a looser piston cylinder fit the a WL? And what would that be?

[Rubone]

Would a servi-car run a looser piston cylinder fit the a WL?

No, they were both considered extreme duty units. Aftermarket pistons generally require more clearance. Break-in specs are the same.

[tracerbob]

That works for me since I have a set of NOS std and .010 piston sets.