Easiest way to find out what my engine bottom end is??

[Madsimilius]

I'm building my engine for big bhp and rpm, and i wanna find out what rods i have.
I'm of 2 ways
1. I'm wondering if i can find out from taking the oil sump plate off?
2. taking of the cam housing and one top and cylinder.

I was told this was built for a high revving race engine, but i don't trust the guy i bought it from as he didn't build it, and didn't seem to know much about cars at all :P
I know it has some aftermarket valve springs and titanium retainers, and that it has a 911sc crank and 3.3 cylinders.

I'm suspecting that it has sc rods with 23mm pin bore.
In that case i've been lucky , as my tach needle has seen 8500 several times in first gear, and usually closer to eight

After i converted it to EFI last summer i started to read more, i got scared and put the rev limiter 7000rpm, but i wanna set it higher again so i´m hoping to find some good parts in there

One more thing i´m wondering about. can i in anyway identify what kind of head bolts i have without taking them of? My car has been boosting 1.2bar since before i got it, so from what i read they better have been changed. But again i don't trust the guy who had it