JDM 6 bolt, cyclone intake, head differences?

[gixx1000]

Hi all,
I've searched and searched, but can't find an answer to my specific question. The 91 GSX that I bought came with a JDM 6 bolt engine and the cyclone intake. The previous owner had some rigged way to open the cyclone intake butterflies without using the vacuum canister that is usually required. I think it is just using boost pressure to open the butterflies. I think this is causing an annoying jerkiness when letting off the gas at highway cruise speeds when the butterflies slam shut from sudden loss of boost transitioning to vacuum. I'm going to try just capping of the actuator vacuum line so the butterflies are open all the time. My question is, if I buy a 1G USDM intake manifold to swap out the cyclone, are there any problems I'm going to run across when swapping to the USDM manifold? Are the ports in the head shaped for the cyclone? I don't want to go through all of the trouble swapping it out, only to end up with a huge vacuum leak at the head.

 

[da_reeseboy]

Just my personal opinion, but I would say spend the money to properly actuate the cyclone intake instead of replacing it. In the intake howto articles, there is an article on properly actuating the jdm cyclone intake. Here's the link - http://www.dsmtuners.com/forums/showthread.php?t=224551. Notice at the bottom of the page the difference it makes in power .
If I remember right, the parts needed for a semi-proper setup for the cyclone intake only costs around $100 (I priced it out a month ago and will be doing it myself by spring)

Just my .02.

- Jesse

P.S. - I forgot to mention that simply capping seems to work since thats how mine currently is and it runs fine (no jerkiness letting off throttle).