The K6 engine had relatively low compression most of the time.
It had RC 836 pistons that had wider crowns, chambers had to be widened making them +24cc.
Those pistons replaced by Action Fours pistons for stock chambers ca: 22.5cc. They were 1.5mm lower plus not as wide domes.
So compression were much lower. Maybe close to CB750 stock. No surprise wheelies when twisting the throttle on 1st 2nd gear, then with VM 29 carbs.
Later stock carbs due to cracking carb boots, AF pistons. Higher speeds still OK. Good acceleration.
Compression test I made with the NOS RC836 pistons with RC295 cam were 175-190PSI. (Same head as before)
Same cheap comp tester on my K2 with CI stock 736 pistons and stock K6 head 150-160 PSI. Same engine with CI +0.50mm K7 pistons +170 PSI.
CI 65 mm pistons will increase the compression.
Thinner base gasket as RCS 0.001" will lower cylinder 0.25 mm.
It ran fine anyway. Probably a better tourer.
I wrote a post about it when I restored the bike after +20 years sleep 2012-2013.
Here with Mikuni TMR 32 carbs. Wrong needles there, found the correct years later.
http://forums.sohc4.net/index.php/topic,104925.msg1173151.html#msg1173151I found NOS RC pistons older than mine with crowns matching the ported head.
Dyno with SS1 cam and the better matching RC836. It reached 10k rpm at that dyno.
From that dyno run
The SS1 cam have not much duration and overlap.
I used 34mm in valves. So valve to valve is no problem.
RC 315 (DP 315) was very close years later.
(RC295 much better cam, more valve to valve clearance and better power from low to high rpm.).
So the SS1 cam will be fine.
About compression.
My K6 a few years later with 1005cc did not reach +100Whp until compression reached a little over 200 PSI with same tester. Then Megacycle 125-75 cam.
Thinner gaskets, 210-215 PSI and around 105 whp. Another ported head with 33.5/28.5mm valves delivered same power and even a few more with 970cc bore