Which is the best E-7 variant engine to use in my '89 CH613 Tandem axle tractor?

[coastaldm611]

My '89 CH613 tractor has 4:42 rears which seem fine, and suitably versatile. I have, but not as yet installed, a used T-2180-B 18 speed trans which is in good/excellent condition, to replace the present transmission which is a "T-107". It's really a high(er) range 4 speed, over a lower 3 speed gear set, w/a single range reverse gear. I'm thinking that the 18-speed T-2180-B trans will likely solve the present problem of the truck just not having enough gears to run and work at anything like an optimum level. I HOPE! My present thinking is that it may be I will - not - need to replace the E7-300 engine w/a more powerful: E7-400, or a 427 or perhaps 454. Your thoughts if so, as to which one? I will add here, that I have been reading that it seems there are some Q's about the E7-460 variant being not reliable or being in some fashion(s) perhaps problematic. Can anyone speak to the '460' issue? So, 2 questions in my mind:

1: Does it seem likely that the benefit of replacing the '7-speed' w/the T-2180B 18speed will be sufficient to NOT require that I also replace the E7-300 engine for one of higher HP? 

2: As noted above, IF it seems to be the case that it will still require an engine swap to one of a larger HP, which of the 3: E7-400, E7-427 or, the E7-454 would the readers think best, and the reason they feel so, and, while we're at it - do they think there are any other options I've overlooked and which I should consider before moving on this? thx! Ed

[BOBWhite]

With more gears you can keep that E7-300 in its power band and it will be better than the 7-speed. I'd say put the 18 speed in and see how it feels before thinking of an engine swap.

Finding a higher horsepower mechanical or PLN E7 might be kind of tricky unless you want to go with an E-Tech. Lots more wiring and modules to track down on the later engines to unless you have a donor truck.