Mopar purple .528 for a 383?

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MopaR&D said:
Nice what kind of aluminum heads? Regardless of brand/type they should have smaller closed chambers than the 906s which will give you a nice bump in compression and much better knock resistance. The Edelbrocks on my 360 are the "open" chamber (more like recessed closed chamber) versions intended for positive-deck 340 pistons but I'm running them on a 5.9L Magnum short block with stock pistons .050" below deck. I've accidentally had the initial+mechanical advance as high as 44 degrees BTDC (on 85-octane regular gas at 5000' elevation) and not once did I ever hear pinging. No shiny specks on the plugs either. I currently run 87-octane regular pump gas near sea level with 36 degrees and it screams with no signs of detonation.

On the other hand the 360 in my D200 pickup has stock open-chamber iron heads and stock cam with around 8.2:1 compression and that will ping when it's hot out with the total advance at 32 degrees, go figure. I'm about to put a colder (180-degree) thermostat in it to help with that.
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Speedmaster victor copies, from a member on here, he did a bunch of work on the to make them “right” on the low deck. I’m getting the heads, offset roller rockers and pushrods. I needed rockers and pushrods for the solid cam anyway and this was a no brainer.

I just have to check everything very close. I have to look out for piston to valve, and valve/bore shrouding. Then I need to see how big of a compression bump I’m in for.
 
MidnightSwinger said:
Speedmaster victor copies, from a member on here, he did a bunch of work on the to make them “right” on the low deck. I’m getting the heads, offset roller rockers and pushrods. I needed rockers and pushrods for the solid cam anyway and this was a no brainer.

I just have to check everything very close. I have to look out for piston to valve, and valve/bore shrouding. Then I need to see how big of a compression bump I’m in for.
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That'll be a BIG upgrade from 906s. Engine Masters did a test on a 440 with Trick Flow 240 vs 270 heads and the bigger heads had gains pretty much everywhere. I do hear P-V clearance can be tricky with factory high-comp 383 pistons though if they don't have valve reliefs. Quite a big intake port to feed 383 cubes but if the rest of the combo is right it'll be a real screamer.
 
MopaR&D said:
That'll be a BIG upgrade from 906s. Engine Masters did a test on a 440 with Trick Flow 240 vs 270 heads and the bigger heads had gains pretty much everywhere. I do hear P-V clearance can be tricky with factory high-comp 383 pistons though if they don't have valve reliefs. Quite a big intake port to feed 383 cubes but if the rest of the combo is right it'll be a real screamer.
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The trick flow intake should be well suited to the heads,lots of plenum, and if I get the right carb, I think it will be pretty sweet.

No doubt a bit “much” for a stock stroke 383 with that .528. I’m hoping the high compression from the smaller closed chamber and the 4 speed/3.91’s that it ends up being a real handful.
 
MidnightSwinger said:
The trick flow intake should be well suited to the heads,lots of plenum, and if I get the right carb, I think it will be pretty sweet.

No doubt a bit “much” for a stock stroke 383 with that .528. I’m hoping the high compression from the smaller closed chamber and the 4 speed/3.91’s that it ends up being a real handful.
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The 4-speed and gears will definitely help and also being in a light car. Anything to help it stay out of the lower revs (<3000 rpm) too much will make it run much better.
 
Going to need more gear 4.30 and 12.1 compression.
Those heads are going to suck all the torque out of a 383, RPM is going to be required for any kind of performance.
IMO the victor copy is a poor choice for a street/strip 383.
 
fishmens67 said:
Going to need more gear 4.30 and 12.1 compression.
Those heads are going to suck all the torque out of a 383, RPM is going to be required for any kind of performance.
IMO the victor copy is a poor choice for a street/strip 383.
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I couldn’t pass up the price, and I might be close on that compression ratio with the flat tops and small chambers.

I have no other ambition for this build than to sound good, look cool, and do big Smokey burn outs. Which should be no problem with the 4 speed and 3.91’s.

If it’s too much for the 383 I guess I’ll just have to get a 440!
 
MidnightSwinger said:
I couldn’t pass up the price, and I might be close on that compression ratio with the flat tops and small chambers.

I have no other ambition for this build than to sound good, look cool, and do big Smokey burn outs. Which should be no problem with the 4 speed and 3.91’s.

If it’s too much for the 383 I guess I’ll just have to get a 440!
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In this 383 build they compare rpm vs victor at 3700 rpm 480 vs 453 lbs-ft lowest they dyno.

The Story Behind Roadkill’s Crop 1970 Plymouth Duster 383
 
I think some are either forgetting or don't know that 528 cam is ground on a 112. As long as you degree it properly, it'll have gobs of bottom end.
 
RustyRatRod said:
I think some are either forgetting or don't know that 528 cam is ground on a 112. As long as you degree it properly, it'll have gobs of bottom end.
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Also, this is a victor copy with a shitty Chinese 1/2 angle valve job. I don’t think they flow like a real victor or max wedge. It will be fun to find out though and I’m still losing 50lbs off the nose of the motor.

A few changes to the build too, the Hedman b body headers are out and I was able to find some ceramic coated Schumacher tri y’s locally.

I sold the street demon, and im
On the hunt for a carb to work with this combo.
 
MidnightSwinger said:
Also, this is a victor copy with a shitty Chinese 1/2 angle valve job. I don’t think they flow like a real victor or max wedge. It will be fun to find out though and I’m still losing 50lbs off the nose of the motor.

A few changes to the build too, the Hedman b body headers are out and I was able to find some ceramic coated Schumacher tri y’s locally.

I sold the street demon, and im
On the hunt for a carb to work with this combo.
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...and the street demon wouldn't why?
 
MidnightSwinger said:
Woah, what hype and bs? I just want to build this thing and have fun.
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You were headed that way. That intake you snatched off is the tits. No way would I have swapped. But hey. It's your project. Have fun with it!
 
RustyRatRod said:
You were headed that way. That intake you snatched off is the tits. No way would I have swapped. But hey. It's your project. Have fun with it!
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the trick flow has a pretty nick rack if I say so myself, but it’s her *** end that made me want to pair it with the victor heads.
 
Comparison

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MidnightSwinger said:
the trick flow has a pretty nick rack if I say so myself, but it’s her *** end that made me want to pair it with the victor heads.
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I missed the whole Victor head thing. My bad. I've been laid up in the bed trying to nurse a hurt back so I haven't been on as much.
 
RustyRatRod said:
I missed the whole Victor head thing. My bad. I've been laid up in the bed trying to nurse a hurt back so I haven't been on as much.
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Your good man, I just had a bunch of crazy deals fall into my lap so it’s taken on a whole evolution. I’d keep the DP4B and everything else if I didn’t just buy the heads and headers.
 
MidnightSwinger said:
Your good man, I just had a bunch of crazy deals fall into my lap so it’s taken on a whole evolution. I’d keep the DP4B and everything else if I didn’t just buy the heads and headers.
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Are you sticking with the MP cam? IMO, it'll be undercammed for those heads and intake, BUT it will be a pavement peelin SOB. I'd run it. It'll be a hoot.
 
RustyRatRod said:
Are you sticking with the MP cam? IMO, it'll be undercammed for those heads and intake, BUT it will be a pavement peelin SOB. I'd run it. It'll be a hoot.
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Yeah I’m gonna run it. Everything is a compromise, so I’ll go with undercammed I guess. I hope you are right!
 
MidnightSwinger said:
I couldn’t pass up the price, and I might be close on that compression ratio with the flat tops and small chambers.

I have no other ambition for this build than to sound good, look cool, and do big Smokey burn outs. Which should be no problem with the 4 speed and 3.91’s.

If it’s too much for the 383 I guess I’ll just have to get a 440!
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What are the chambers?
 
MOPARMAGA said:
Assuming it's a standard bore, assuming flat top no valve relief pistons, assuming true stroke 3.375 same for rod length, combustion chamber and other variables you'll be around 10.5-10.6
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Thanks man, that sounds perfect. It’s .030 over bore but that should change the number too much. I could always go with a thicker head gasket to knock it down some if needed.
 
MidnightSwinger said:
Thanks man, that sounds perfect. It’s .030 over bore but that should change the number too much. I could always go with a thicker head gasket to knock it down some if needed.
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.030 of bore usually gets an additional point in compression or close so I'd run a .039 gasket.
Hopefully since the block has been machined it has been decked and is .000 deck and decent pistons were used. .039 gasket would put you at 10.2 if it were me I'd shoot for the higher but California probably has **** gas on purpose
 
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