383 engine combo recommendation

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f1shman

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A friend of mine is throwing together a parts list for a 383 he wants to build. This engine will be going into a 1971 Monte Carlo (very heavy) that sees a good amount of street time in the summer and some track use. If you would be so kind as to take a gander at the list and tell me if anything sounds like it doesn't belong or could be improved upon I'd appreciate it. He wants to keep the compression low to run 87 octane, 89 at most.

Speed Demon 750 cfm with mechanical secondaries
Edelbrock RPM air-gap
Trick Flow heads 215cc runners, 2.08/1.6 valves, 64cc chambers
Comp Cam XR270HR 270/276 110* LSA (hydraulic roller cam)
1.6:1 roller rockers
Pertronix flame-thrower HEI
1 5/8 long tube headers, dual exhaust
383 Forged Scat rolling assembly that he number crunched to 9.84:1 CR, 7.88:1 dynamic
TH400 stock stall
4.11:1
 

HotRodPC

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Could always go with a bit bigger cam with a higher static comp ratio, and dynamically it be lower. Pretty much looks like an RV motor to me. Most stock converter rebuilders also make a high stall converter. Basically its a stock converter with just a few hundred more rpm stall. Maybe like a 2000 rpm instead of 1600-1800.
 

f1shman

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That's what I was thinking. The heads are way overkill for just a 270 duration bumpstick, and I think he'll be happier with moving the powerband to a higher RPM considering the gearing he has in the car already.
 

HotRodPC

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Yeah, he's got a good valvetrain picked out with lots of potential, but the cam is going to be what creates the bottleneck in this case where most guys put a biggo cam and the heads are the bottleneck.
He could also go with a higher compression piston and still run pump gas if he chose a cam with some vavle overlap. The AirGap intake and 750cfm carb should run OK with all that too.
 

Manbearpig

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That's what I was thinking. The heads are way overkill for just a 270 duration bumpstick, and I think he'll be happier with moving the powerband to a higher RPM considering the gearing he has in the car already.

:word:

With those heads I think a cam in the 23x duration @ .050" would make him happier
 

f1shman

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Pretty much looks like an RV motor to me.

I think he was looking for high torque numbers at first since the car is such a boat. I have no idea what is possessing him to get the heads though. He must have a line on a heck of a deal to buy them from someone.

I'm sending him a follow up email with these changes:

Comp Cams XR282HR 282/288 110* LSA (230/236 @ .050)
TCI Breakaway 2400 stall 11" converter

Now back to my regularly scheduled beverage. :drunk:
 

85k10383

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He could always grow into the heads so to speak. I would like to get a little more cam for my 383 but don't really know where to begin. And all that extra torque does come in awful handy LOL
 

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