[cyprus73]

Hi All.

Just wondering if the port size on the inlet manifold of a g13a is the same as
on a g16a?

I know there is a difference on it where the carby bolts up re water jacket but not sure
of ports.

I have a g16a in my Sierra now and a spare g13a manifold in the garage that I want to do
some mods on and install a weber, but not sure on the port sizes being the same.

Thks
Chris.

[jdk81]

IIRC g16a is slightly bigger.

Personally I wouldnt bother.
While i investigated a lot of options and did some testing and work with the stock sierra carby and a few other things, in hindsight I know I should have saved the coin and gone g16b sooner.
All that other shit wasn't worth the time, effort and $.

I know now (on my 4th sierra) to tolerate a sh*tbag running carby g13a until I can g16b it.

[Santos]

from memory its a 1mm difference
i think the sierra manifold is better as the 4 intake runners are even length
using epoxy putty i added certain features that the g16a intake had to the sierra one

smaller chamber below carb with less dead zones, sort of like an internal throttle plate spacer. Done it to two intakes. Held up the for the last 5 years.