Ive been slowly turning my savage into a racer, last week my engine died (RIP 4.6SS 2005-2007 YES IT LASTED THAT LONG).
I could buy a piston and sleeve for the 4.6SS and get it ported. OR what i really want to do is buy a new engine but not the typical brands, im making a list of new ones that ive seen around, so far ive found:

Axial

.28 either the Spec1S or Spec1RR havent decided yet

SH

Type: PT2803A-P6
Cublic cpapcity 4.57 cc
Bore 18.50 mm
Stroke 17.00 mm
R.P.M 34000
Power 3.8 ps
Weight 400 g

STS

D28M (#2801*)
Monster Truck Engine
Cylinder Contents 4.66cc
Bore: 18.80mm / Stroke:16.80mm
Crankshaft : 14mm SG type
Carburetor: 2 Needles Slide 9 mm
Piston / Sleeve: ABC 3P
Glow-plug : Standard

what would you choose (including the ported hpi 4.6SS) and why? if you have one of these engines please share any information with me, and also can you recommend any other brand .28 engine for me to look at and also give me your experience with it if possible. thanks all.