If you've already got an OS 40 LA, then ignore this, but I've always been less than impressed with that engine - I think the OS 46 FX is almost worth the money, but if you're on a budget, I'd suggest you consider a cheaper non-OS .46 sized engine from one of the other manufacturers like Magnum, ASP etc. These days the quality is on par with OS and you get a lot more performance for your money.

Hope your Tracer goes well - I'll have to go check it out now...