RE: gonna buy a engine tonight need help!!
I've had both. The Axial RR was a total PIA for the first gallon and a half, but then became really nice for the next 4-5 gallons in my Savage. Early on I had it in my Muggy and it just didn't cut it(to be fair I was running a Savage pipe and header - on the wrong side, and maybe this killed it. It ripped in my 3-speed Savage though..) I then got an LRP with JP-2 pipe for the Muggy, and this has been my all-time favorite engine/pipe combo.
So I would get the LRP Spec 3 truggy version - not only based on my experience either. But LOTS of people rave about the LRP in all kinds of trucks... It's probably the most popular 28, and not without reason IMO..