Inliners International Forums General Discussion Engines Gmc 270 timing and tdc

Hi!

I am trying to get a gmc 270 to run alittle better.
As of right now it runs, but i feel something is not quite right, the symptoms are:
Very low power, occational backfire under load (especially at wot) poor mpg..
The engine does not make any strange noises, just seems to respond slow.

My first thought is to check out the timing, and here are my questions for you tech guys:
Which is the no 1 cylinder, the one closest to the radiator or the one closest to the rear?
I have a peep hole on the drivers side bellhousing, is this for finding tdc and setting the timing or are there other places to check?
What is the firing order for a gmc 270?

Thank you in advance,
Fred