I was wondering that when I install my new valves and springs should cylinder #1 be at tdc?

 

???

Heads are off when you install valves and springs, and if its a SOHC then cams are off as well, so no connection to TDC

 

Ok I just wanted to make sure that I don't make piston contact. So I still will be able to adjust timing once the heads are on?

 

Yes.

You put crank at #1 TDC, then install the heads
Then install the the cams and chains in their #1 TDC positions

So no valve strike would happen

 

Ok thanks now just to be sure when you say tdc I've noticed that if I turn the crank enough the piston will flush with the engine block. Is that to much? Or should I lower it to where the key way on the crank is at 12oclock?

 

Top dead center(TDC) means a piston's top is flush with block

At #1 TDC, #1 and #5 pistons will be flush with block, they are a matched set to balance the engine's rotating mass



2 and 6 will be at TDC at the same time, and then 3 and 4 will be at TDC at the same time, each of the 3 matched sets are 120deg apart in one rotation of the crank shaft, for 360deg full rotation

#1 TDC is used because............well you have to pick some place to start and #1 TDC is what has been used for 100+ years to time 4-stroke engines
But there is #2 TDC, #3 TDC, #4 TDC, ect

 

I appreciate that!!