[neon_rt]

You will just have to check the junk yards.
I think you can use the MTX from the first Gen Neons also.
The gear ratio for the SOHC is 3.54 and the gear ratio for the Dohc is 3.94.
The OD ratio on both sohc and dohc is the same .72 except for the R/T and ACR models in which the OD ratio is .81.
If you should decide to use a Dohc transmission, be aware that even though the performance feels stronger (b/c of the lower gears) it has been reported that 1/4 mile times are not quite as good b/c you can't finish in 3rd gear, you lose time shifting into 4th.