350 Holley

TXcoupe · petrol head Joined: 05 Oct 2001 Posts: 1675

hey has oanyone put a 350 holley on there gem?? did they use the sigma adapter plate to do itor get a custom made one?

Mark · tinkerer Joined: 04 Oct 2001 Posts: 153

Yes, use the sigma adaptor, bolt it to the standard manifold, port the inside out to suit, and you then have to fit a 1/2inch riser plate to make the accelerator pump clear the thermostat housing. They work an absolute treat.
I just had one roll on a dynomax dyno, standard 2litre bottom end,ported 1600 head, 425 thou lift cam, port matched inlet manifold with a 350 holley and it rolled 138.9hp at the wheels. It loves the holley.

TXcoupe · petrol head Joined: 05 Oct 2001 Posts: 1675

sweeeeeeeeeeeeeet as might do that next week coz i got me tax return and the damn RPM clutch didn't turn up Damn coventry's

Fastgem · tinkerer Joined: 04 Oct 2001 Posts: 166

I put one on a 2ltr a few weeks back. A 32/36 weber can flow 300cfm so there not all that much bigger. Found the mid range was better but wasn't as much as i was expecting, still go a good set of twin webers over the 350 holley (I don’t think the holley was quite as good as a 40 dfav weber). As long as you have a remote reservoir then you shouldn’t need a riser plate for the accelerator pump to clear the thermostat, just mount the carb around the other way so the fuel intake is facing the driver, might need a slightly longer fuel hose but meh.. But If you dont have a remote brake fluid reservoir then it gets in the way of the throttle leaver hence needing the riser plate.
I just got one of the universal adaptors from repco - just drill your own holes to match up to the gemini manifold, was like $25 and also used 2 of those black plastic spacers and reshaped them and the manifold to get a nice air flow through it.