They used to call the 253 the bird scarers problably around the time they went into HX's with the pollution gear. I have a 253 in my HZ VAN, bored out to 80 thou, mild cam, 4 speed [m21 I think], 3.08 diff, 4barrel rotcheaster , electronic ignition.The crank,fly wheel, clutch, pistons, & con rods were all balanced.The heads have larger valves than standard & the intake manafold was port matched.It may be a little tall in 1st gear on a hill but if you are carefull with clutch it is ok .Anyway the above combination does it for me it ticks over very nicely & run down the road & passes with ease.Off coarse its no match for a 290 KW BF GT. RB