Yep, if you install your 250 head onto your 194 you would loose about 1 point of compression.
The 194 does not have high comprssion,correct? 8.5ish?
I would just keep the compression where it is at run lower boost pressure,under 10 psi approx,& use a methanol injection set-up on pump gas.
Running a desent CR of 8.5-9.0 will make your 194 a little more zippy rather to drop a point of compression to 7.5:1 (w/a 250 head) will be lazy.
So far I run up to 24 psi of boost pressure on my street Syclone on pump gas,but it also has a built in knock sensor that will retard the timing automatically along w/a J&S safe gaurd. A little spendy ,but saves your engine from detonation & self destruction.
http://www.jandssafeguard.com/Most people that want high performance turbo or supercharger on the street on pump gas,,,all use some sort of methanol injection,,,cant figure out why people here do not seem interested in it though..
I will say this,once you try methanol injection,,,you wont be needing race gas anymore ,for the most part.
You'll be asking yourself,,,why didn't I install a methanol injection kit a long time ago?
As of now my pump gas street Syclone runs 12 flat,,,w/out meth & pump gas,it would be running mid to high 13's.
It is like a chemicle intercooler plus methanol has a higher octane value.
http://www.alcohol-injection.com/water-injection-kits-1/universal-19/http://www.coolingmist.com/http://www.alkycontrol.com/http://www.google.com/products?sourceid=...on&um=1&ie=UTF-http://www.aquamist.co.uk/8&ei=RRQUS83tLomMswP43qnDAQ&sa=X&oi=product_result_group&ct=title&resnum=4&ved=0CCsQrQQwAw
Hope this help a bit.
MBHD
