rb25det intake manifold on a rb20det engine

[Jedi_Nismo]

hey guys i was wondering if it can be done. a rb25det intake manifold onto a rb20det engine?? i got a free manifold from my friend so i thought i might try it out since i hate how the throttle body n pipe are on top of the valve cover. i did some searching and found out it cant be used but no reason why. when i looked at pictures of the two it looks the same. can u guys tell me why it cant be used? also if it can be used what can i do make it work right? like if a machine shop can make it work. thanks

[Gabes13]

The flanges are different; the rb20 is a 14 bolt, the 25 is 13 (or 15, cant remember). Plus the ports for the 25 are WAY larger than the 20. You might be able to cut and weld the rb20 flange onto the rb25 manifold but the symmetry is different.

EDIT:

Here
s a 20 head with a 25 gasket:

[Jedi_Nismo]

oh ok cool thanks. i think i should just try to sell the rb25 manifold so i can get a rb20 one instead hahahaa

[USMCgetsome]

i'm confident in saying that a rb26dett intake manifold would fit

[Carl H]

I will have my RIPS rb20 specific manifold for sale here shortly...pm for details.

[StricNyne]

Dude ... the intake that CarlH is selling is flipping insane i doubt there is more than 10 in the US for the RB20 there is nothing that compares to the RIPS