My cosworth manifold has started leaking on one end cap (following use of methanol spray). And I've noticed my vacuum at idle decreased a single psi (usually -6.5 psi, now -5.5 psi). Just something to consider. I've been meaning to PM you about getting some gaskets to redo it Sharif.

 

i dunno i pulled 20in Hg with my C2's with an 850rpm idle. If the idle was over 1000 like during warmup, it would only be around 15