Hi all, I have a 73 Fiat 500R and over the last summer, one by one all of my wheel cylinders started to seize up on me. I removed all four and ordered new ones from MrFiat for the 500R. 23mm fronts and 15mm rears which match the ones I already had on the car. The rear ones went in just fine with room for the drum to spin freely but once I replaced the fronts I am unable to put the Drum back on due to the cylinders not retracting in or back enough to allow the shoes to fit inside the drums. After taking the old ones and new ones apart I noticed that the new cylinders have longer pistons in them then the originals and they end up touching each other inside the cylinder when compressed all in the way. Does anyone know if these cylinders come in different piston lengths and which ones should I be ordering?