Found this thread on jalopyjournal, lots of propane hotrods running around apparently, especailly in OZ and NZ.
http://www.jalopyjournal.com/forum/showthread.php?t=290927&page=5
Here are some dyno pulls and a quote from a company called Fastco
New LPG Chevy street rod & race engines from MILD TO WILD dyno tested & tuned 100% turn key , full show dressed.
Chevy 355cid / 360+ BHP LPG engines priced @ $5700 USD turn key..........
Our LPG engines are built from the ground up for LPG fuel, the system we use is IMPCO with high flow diaphram..we use high compression pistons in these engines @ 11:1 comp a must for LPG engines to take advantage of LPG octane of 108+ greatly increasing BHP & torque output & MPG of engine , we install a custom ground hyd roller cam for LPG application. plasma moly rings file fit a must for LPG app's, Liberty severe duty SS valves installed in alum heads... because of high exhaust tempetures with LPG engines stock or mild performance type valves cannot be used.
A high output ignition system must be used on LPG engines we use new Revolution HEI dizzy with 60,000 volt coil & ATE 1200 6AL amp box ...wired a must use addition with LPG engines for fast clean starts & much better MPG
SBC 355 cid / 360+ BHP LPG engine / dyno tested & tuned 100% turn key priced @ $ 5700 USD
Who says GREEN cannot be MEAN.......... NOT US ! we make go'n green tons of hot rod'n fun.
E-mail us @ fastcoauto@aol.com for more information & details on our custom built LPG engines.... and a LPG engine to suit your application
I'm not sure what mixer they are using, but I'm sending an email to ask. They are in New York state.
This one they are claiming 380 Hp (single mixer setup) and pulling to 6000rpm
http://s4.beta.photobucket.com/user/fastco/media/PETESMEANGREENMACHINEDYNOTEST.mp4.html#/user/fastco/media/PETESMEANGREENMACHINEDYNOTEST.mp4.html?&_suid=13534695413320683284865130159
