Re: 360 BUILD UP
I do believe that the 390~401 have thicker webbing in the main cap area, allowing the installation of 4 bolt caps if desired. I also believe that the 390 and 401s casting is nearly identical to the 360 "beefy block" that was released in 1970 and had an extremely low production run, just enough to validate it for TransAm, NASCAR, and NHRA use.
To make some ponies with the 360, first you have to decide what rev range you want to use. Also, the higher reving builds need to have a "loose" converter and a revy rear gear.
* Redline at 6000 - stock cast pistons (9 to 1), "3/4" cam and kit, 3-angle valve job, dual plane aluminum Performer style intake, Holley 3310 vac sec. 4bbl. and electric fuel pump, small tube headers, electronic ignition, 3.54 rear gear.
* Redline at 7000 - cast pistons could be used, forged are better (10 to 1), ARP rod bolts would be nice, oil mods to supply the rear mains with more oil, oil mod to supply the distributor gear, lumpier cam and kit, good dual row roller timing chain, good comp valve job and clean up the ports, single plane Torker style intake, could use the 3310, or use a 750 to 850 double pumper if using a loose converter or stick and a 4.10 rear gear, big tube headers, electronic ignition and a MSD 6AL box.
* Redline at 8000 - same as above but go another step on the cam and kit (follow cam maker's recommendation), 10.5~1 forged pistons are now mandatory and since you are buying pistons, go with smallblock Chevy pistons and Eagle H-beam (sbc) rods (the big end will need to be milled a lil thinner), a 4.56 or 4.88 gear to get out of the hole. Some additional crankcase vents should be added to the valve covers.
Roller rockers, stud girdle and tall valve covers could be added to any of these builds. Titanium retainers, hardened pushrods, lash caps, etc. can also be added if $$$ permits.
Of course, these recomendations are very general, and I am assuming that we are starting with a set of heads from a 360 or 401 that have the big valves and screw in rocker studs. Also assuming competant machine shop services that include resizing the rods and balancing the rotating assy. The gearing sugestions are for a rwd car and std diameter tires. You will have to calc this for your setup. Just remember that most anything you add at the top of the powerband will be lost from the bottom, and you have to gear it for good launches. The looser torque converter is so we can get the motor into the meaty part of the power band at launch. generally speaking, a smaller converter launches at a higher speed. I've heard of people sticking vega converters into TH350s and 400s to get a better launch. I would also advise you to either wrap your bellhousing with a transmission blanket or use a "rigid" bellhousing cover for automatics, and use a scattershield when building a stick shift car. A friend of mine had the converter or parts of it blow up thru the floor, thru the pass seat, and dent the roof of his car last year. He got to keep his feet, this time.
Well, I'm sure that I forgot to write something, but I'm getting thirsty, so......bye