Conversion to tubeless tires - 51 Chrysler

We have had tubeless radial tires installed on our 1951 Chrysler New Yorker. The dealer used standard rubber valve stems. Unfortunately, the valve-stem holes in the wheels are oval-shaped and therefore too large for the stems used, so when a front hubcap crept backward it pulled the stem from the hole and the tire went flat.

A metal truck-type stem has an oval rubber seat, but the seat is too large for my wheels; the dealer declines to either modify it or install it by compression only, due to liability issues. If I used inner tubes, the stems would still not fit my holes, even with (round) plastic grommets.

How have other owners dealt with this issue? Trying to modify the holes by welding seems crude and dangerous. If the only answer is new wheels, where can I find wheels with the same bolt pattern?

Ron R.

There are 2 things you need...first I went to Town Fair Tires and they removed the tubes in both my Imperial and De Soto. They put in large oval valve stems and they worked great on the Imperial...not so great on the De Soto...tires kept going flat...so I brought it back and they put some sort of sealant around the hole and the tire has not lost air since. I drove the car to Ohio and back with no problems.

Second there is a MoPar accessory that occasionally shows up on Ebay that is a metal sleeve that fits over the valve stem and is the exact size for the wheelcover hole. This prevents the cover from "walking" and breaking the valvestem. It came on the Imperial and I added it to the De Soto..again problem free