Sara is right, the only reason I chose not to use the autostart is because this would ruin the effect by having the starter stick out the front of the nacelles since Peter had doen such a nice job of making a removeable FOD screen in the nacelles, and I did not want that. Wren went out of their way to help me. Peter had no probelms with the manual starters, but I am too clumsy and it was awkward for me, so I opted for the air start, which is something I knew I could get the hang of, but it does require you to lug a big tank around with you.
Eddie, the Wren are really swallowed by the nacelles, so you should have no problems fitting them in there. These little engine have so much power and in the airliners a .6:1 ratio is about right. This airliner flies at half throttle. They sip fuel, so you don't have to have a huge fuel load on bard unless you want to make an intercontinental flight. You are right that the DC-8 pod is slimmer than the nacelles of the Airbus or the Boeing, so you would have to get the dimensions to make sure they will fit, but the Wrens are extremely small engines, and with the manual version they are even smaller. Sara and Roger can give you all the dimensions you need and the specs on the engines.