stock gsr compression is 10.0:1. type r is about 10.8:1 usdm. jdm r is in the low 11:1 range. if you slap b16 pistons in there on ls rods u will be in the mid to high 11:1 range (it depends on the head/pistons you use). as for the 75-80 shot....i kno someone runnin a 65 shot on a stock single cam bottom end and hasnt had any problems for quite a while. ull be fine on stock internals, especially with bigger rod bolts and new bearings. ive also seen an h22 run on an 85 shot for a long time as well bone stock.

the reason i say b16 pistons is bc there is no modification needed to have them press fit onto an ls rod. type r pistons will require the small end of the rod to be milled a tad for them to be pressed on. its a lot of hassle. you will be safe on the oem internals as long as its tuned right.