Both Strykers are usually run with 25cc gas engines. These days modified Zenoahs produce around 6 1/2 hp and Quickdraws produce over 7 1/2 hp. This is probably more than a 90 nitro engine on a good day. A Zenoah with a steel pipe weighs 4 1/2 pounds. From the above, I see no reason why the hull won't handle twin 84s, but you will have a lot more problems than you would have with a modified Zenoah. The first and operating costs would be less with the gas engine as well.
Lohring Miller