Hi people Im AL from accross the pond and I have an escaped Iroc-z 305tpi. Read posts for ages now on here and they're a great source of advice, but I have a question now I cant find an answer to. I just with the help of a mate installed the NOStpi kit (what a great kit it is I reccommend it to anyone.) Ran it the other night a few times on a 100 shot and its great. We didnt have time to change the plugs so they were stock. The instructions said it was ok, and in any event ive got some delco r42ts's to put in before the next run. My question is thus and it's to do with being in England. Over here we have 95 octane as standard and can get 99 on tap as premium. (Before you all get jealous it works out at about $10 a gallon ) I know but thats another political story. Obviously higher octane fuel reduces detonation and those kits were designed to run on your juice. So given the fact my engine is healthy and 99 is available, Im tempted to try the 150 shot jet. It says only for 350's but is there really much difference between a stock 350 and 305 (in terms of components etc)?. Any thoughts on wether I can use the 150 shot on 99 would be great. Oh and ive retarded the timing aswell from 6 to 2 degrees to sort of get a balance between on and off the juice.

Look into how your fuel octane is rated. You may be unhappily surprised at your $/octane. Figure out your octane in US standards before thinking of doing the 150HP shot.

We are all corn farmers now so we can get E85 which is about 105 octane for $3/gallon.

how do i figure it out in US standards? we get rinsed over here for fuel. just that reading in the kit its designed for your premium 93... dont doubt yuo can get 105 but the kit is assuming 93

Overseas uses RON method. USA uses (RON+MON)/2. MON is usually about 8 octane lower than RON so.............

if your RON is 99, assume MON is 99-8 = 91. Then (99+91)/2 = 95 octane is US standards. You have enough octane to support a 150HP shot. Will your setup really handle a 150HP shot.......that I don't know.

Thanks for that. I have to put up with so many stupid comments over here about american cars and their leafs and the fuel you use etc. Im surrounded by ignoramouses that don't respect the V to the 8 and simply dont know. You learn something every day and Im glad you told me that. Just gives me more facts to silence these know it alls with. I'm not going to try 150 just yet if at all yet.