hi ron, many thanks ,dont intend using muffler pressure ,according to laser man its not required.Did you run yours on pressure? Looking as though i will need to pack the engine mount a good way to achieve correct cowl alignment,will use some good quality ply.Not really keen on using dowels as the chap did at beginning of thread,may be perfectly a.o.k, but i prefer something more substanshle,maybe why my models always end up on the heavy side.What does yours weigh? all the best, frank