i would not put in the 1.74 valve unless your going to do some port work. get the best valve job you can and the right valve springs it will run good with the right cam. am running the 1.6 valve with a 446 engine you will only have 388.
I am running 915 heads with the 1.60 exhaust valves pulls to 5200 rpms with no problem. and with a smaller 217-221 cam and 2.94 gears goes side ways off the line or even going 10 mph.
to run the alum heads you should have about 10.25 compression. if you have lower compression with that good size 230-236 cam and bigger port heads you will have no low end torque
comp says 1.90 height.I bet the springs are 911 on the alum heads too. I am using the 911 springs and at 1.87 height they come in at 127 seat and 309 at .500 lift.
I didn't read your post right. i thought it said .010 deck height not that you cut .010 off the block. so where are the pistons in the hole or what is your pin height ? you need to know what your compression is going to be.
if the pistons don't have valve reliefs your going be about 9.65 compression about right for iron heads. for alum heads that is going to be on the low side.
you don't want to hone the lifter bores just to hone them. too much clearance will cause low oil pressure at idle. the lifters should be checked to make sure they slide in before honing. they should have cleaned up the oil return slots a lot of rough metal that might break off.
since it is a 4-speed i would not change gears. if anything go with an inch taller tire. your standard 4-speed is running about 200 or so less rpms than an automatic because of torque converter slip.
somebody tested the log manifolds vs hp manifolds and only a few HP difference. I think the 2.5 inch vs the 2.25 inch log manifolds outlets help more than the design.
left out the most important info. all body panels are original with no rust or repair work. The original floor and trunk are also in excellent condition like the rest of the underneath in excellent condition. very solid car all around with no issues.