RE: E-flite 25 on Pitts model 12
I'm not a real experienced builder, but I had a similar problem. I put eflight .10 on parkflyer cessna skylane 180. The motor stuck out too far to get cowl on. the mount to motor to firewall is wood. I cut the sides off and shortened them keeping the angle the same. I used 3/16 beech a braced the inside with balsa blocks. I used 5 min epoxy on the whole thing and it's strong and tight most important the cowl fits.