u need to decide which crank, then u can work out which rod & piston u need that work with a good ratio 1.7 plus is good ratio.

so if i use an a14 crank do i need a rod 127.5mm? and an a15 needs 125mm?...

the a14 and 127.5mm rod combo would give me 1.65 ratio i think?

can use either crank, weighing up how it would all work.

1200gx man, i'll be posting pics of the welded up manifold soon :)

I would say the best setup that I have heard in the past is the square option whereby the bore and stroke are the same.

Keep us updated on the throttle setup as I am tempted to go that route as well in the future. Through my PM's I think you knew that.

thats none as a square bore set up bore & stroke the same good combo works well. bigger bore with shorter stroke tend to rev harder .rod ratios std a12 1.66 / a14 1.72 /a12rod with a14 stroke 1.57 longer the rod the better.
a14 piston comp height 32.5mm a15 are 30mm so are u using a a14 crank or a15 different strokes different pistons.

OK here's my workings out, not sure if i'm on the right track...

standard
A14 stroke 77mm rod 133mm ratio 1.727
A15 stroke 82mm rod 133mm ratio 1.622

i would need a rod 8mm shorter for the a15 crank and 3mm shorter for the a14 crank...?
A14 stroke 77mm new rod 130mm ratio 1.688
A15 stroke 82mm rew rod 125mm ratio 1.727

or do i have to double the 8mm? i'm starting to confuse myself!

my A14 in the wag was bored 60 thou,this made the bore and stroke the same and was using the standard 1400 rods also balanced bottom end and a 30/70 cam grind,it was good strong and reliable.

which one a14 or a15 different in stroke

wow that is heaps shorter! so not worth the effort? What length rod would i need to get the piston to sit at deck height with an a14 or a15 crank and what rod/stroke ratio would that give me?

a12 rod 121.5mm/17.45 pin & a14/15 rod 133mm/19mm pin {11.5mm different in length]u would need to bore out little end to 19mm but then piston to short.