55,to 57 birds heating.
I have owned 2 55birds ,my friend has a 55 with a 312 ,power, 1 of my 55s had a 312.i took my 55 with 292 to palm springs
no over heating. reason being both birds have new alum radiators.,same old spacer ,my 292 was auto trans(air coold trans.
I did have an elect fan as a stand by for traffic jam or peraids. .1 big issue is water flow.  which means rad watter flow is critical. so called rad shops who say they have clean your rad are cairless. with the. truth. with early birds new rads are a must, with right number of tubes.looking at the new spacer is a big step with the new rads
I âm sure I will get negative  responce. but that  is part of site.the old guy