First... the is no reason for you to ditch the largeport head, as you will be using ITBs. If you were retaining the stock manifold
, it might be worthwhile to run a smallport to achieve your power goals
160hp... or 160whp? - - VERY important difference
ASSUMING the later..... 160whp
Max2503 wrote:I've got an aftermarket ecu running slivertop itbs. I had thought about smallport pistons. On cams, I was thinking of 272 both, or catcams 275/267 setup.
To run those cams(Cat cams listed) the head will perform a WHOLE lot better with port work, the 275 is 10mm of lift, so you MAY need to have the lifter buckets machined for the cam to physically turn.
As to the pistons... You could run either stock 4AGE piston, but why? You are building a performance engine, and unless you have something to prove, I'd look to get a better designed piston (with holes for the oil rings to evacuate oil instead of a slit).
2 things are VERY important with a 7AGE..... 1) as has been mentioned, cam timing. You can purchase a "broached" (re-cut) crankshaft timing pulley, or not - but it is always best to set cam timing AFTER you have confirmed TDC. 2) Set piston squish @ .032" (+ or - .002") - "Squish" is the gap between the top edge of the piston @ TDC, and the flat parts of the combustion chamber.
The crankshaft can likely survive 8500 rpm, the stock rods may.... or may not
, I'd recommend MRP 7AGE rods.
If I were building your engine, I'd recommend big valves(32mm intake, 27.5mm exhaust), and instead of the Catcams 275/267, I'd recommend a set of the big lift(10.7mm) 268 cams. I'd run a custom piston, the crown would be -2cc volume, and MRP rods.