Droff Posted September 21, 2016 Share Posted September 21, 2016 I've been considering putting a 383 into my '71, only for street use, close to a daily driver. I've got a 350 transmission in it and will be going to a posi unit with around 3.42 gears. I ran across a 383 for sale that is in a truck used for racing, mud I think. Around 8-9 runs on the engine. - 4 bolt- Forged flat tops- Scat rotating assembly balanced- Comp cam solid lift camshaft 560 570 lift- World product sportsman 2 heads 2.02 1.60, valves been shaved 0.050, have comp screw in studs an guide plates, 220cc runners, 72cc chambers- 0.80 comp 0.100 longer pushrods- 1.5 comp stainless roller rockers with poly locks- Weiland speed intake- No carb $1500 Compression right now is around 11.5:1, he told me he can run 91 pump gas through it. That cam looks awful rough and the heads look a bit large for a driver. Any opinions on whether this is too much to tame down? Would the it need a head swap and a cam swap? Thanks. Quote Link to comment Share on other sites More sharing options...
MCfan Posted September 21, 2016 Share Posted September 21, 2016 Okay, Drew ... here's my opinion (based on on-going experience) for what it's worth. That engine sounds closer to "street" than "daily driver" to me. If the CR is actually 11.5:1 (or more), I would be highly skeptical of the "91 octane pump gas" claim. The cam may be wild enough to bleed off some of that compression but then you may have other issues for a daily driver. I know there are many factors that combine to cause detonation but high octane fuel is a must for any high compression engine and I seriously doubt 91 will serve you well at WOT. I buy 93 octane pump gas, add 108 octane booster and barely get by with 14 degrees initial advance on my 11.9:1 CR 408. Thankfully, my '70s are fun toys, not daily drivers. Seems unlikely you would be considering a 383 if you didn't intend to open the secondaries occasionally. Others may (and probably will) see it differently, but ... been there, still doin' that! Quote Link to comment Share on other sites More sharing options...
Droff Posted September 23, 2016 Author Share Posted September 23, 2016 Thanks Dennis. I'm not so sure this particular 383 would be in the daily driver category either. I think the price is really pretty good and I'm sure it has a heck of rumble to it but the high compression/pump gas issue scares me a bit. Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted September 23, 2016 Share Posted September 23, 2016 it's a great price, but the compression ratio and being a solid cam, I wouldn't buy it for what you are looking for Quote Link to comment Share on other sites More sharing options...
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