Yes, it's always advisable to mill the intake faces after taking any more than .020, as there are too many tolerance stack up issues that start to negatively affect port and flange alignment past this point. On a whim, I was going to throw out a hand grenade guess (accurate to within 20%) earlier of 345 hp @ 5100 and about 410 lb feet at 3800 rpm. That's close enough to the magazine article results for me to say it here. I don't put a whole lot into what a dyno says though, as real world E.T. will show what a dyno can't. That should be pretty close with the mildly ported 587s with the chambers opened up for the 202 valves, along with the cam and induction from your 340. It's also assuming you got about a 9.2:1 compression ratio with all cylinder pressures within 10% of one another. I think your probably going to have dished pistons below deck, so even with the heads milled .060, .040 is going to be too thick to target that much compression. Which rear axle does it have? I am assuming 8-1/4. For your English countryside roads and four speed, you should really consider stepping up to 3.55 gears in this combination. It would make for a snappy driver with that 360 in that relatively light car.
