im not sure about the mounting for the gas tank.
There was i beleive a tank behind the seat area and at first i just figgured it was an hydraulic reservoir,however it wouldnt have a factory hydraulic anything would it.
Im pretty sure the machines are the same size,but there are some differences for sure.
ill get the missus to help with another pic or 2 of the parts crawler.
thanks again for all the interest.
Chris

There are both Ls or PLs (serial number preifx). The only difference between the L and the PL is were it was made(there were may changes made to parts of the tractor duing the production run). Ls were built in San Lenadro Ca and the PLs were built in Peoria Ill. The way that we talk about Cats is a little confusing at first. When you some one say that they have an 8C Twenty (8C being the serial number prefix) that tells most everyone what Twenty they have. Another example would be the D8 Cat. The D8 has been built for 70 years with many different serial number prefixes 5E, 1H, 8R, 2U, 13A etc. I hope this helps a little when were are talking Ls PLs and 8C Twentys.
Thanks
Ken

My quick look at the one with the horizontal louvers suggested to me that it was an 8C Twenty - but I certainly could be wrong. Yes - the engines would be very different if one was an 8C (small 20) and the other an "L" (or PL) twenty (large 20). Just count the track rollers - 8C has four per side, L has just three.
They may well be both "L" twenties - but that horizontal louver threw me.

PT3090