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Discussion Starter #1
I am at a cross road with my build.

The motor is presently out and the block is bare, ready to be hot tanked.

Initial plans were to keep it simple stock bottom end, do some nice 190 TFS heads and a custom cam=done.

But now my mind has been going to doing a stroker.

How much more power does a 331 make over a 302 on average ? I know 350whp on a 302 with a proper cam and heads is possible.

Can a 331 crack 400whp?


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Yeah sure it can with the right heads cam and intake.
 

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Discussion Starter #4
I’m just wondering if the cost of a new rotating assembly is worth it.

I know 350 whp is happening on many set ups with stock bottom ends.

I just haven’t seen any n/a 331 results.


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I’m just wondering if the cost of a new rotating assembly is worth it.

I know 350 whp is happening on many set ups with stock bottom ends.

I just haven’t seen any n/a 331 results.


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I'm planning on just swapping the heads out on my 331 to 205 11r heads just to see if I can get over the 400 rwhp mark. That's with me reusing my RPM 2 intake, 70mm throttle body, and camshaft I currently have. Honestly I think it's possible with 190 11r heads.

If I get the chance to finally do it, I'll post my results.
 

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Discussion Starter #6
What kinda jam are you putting down now and what set up ?


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What kinda jam are you putting down now and what set up ?


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My last dyno was 326 rwhp 357 tq

That's with box stock Edelbrock Performer 170 cc heads, RPM 2 intake, 70 mm throttle body, xe274hr comp cam and MAC short tube headers. This is with 30 pound injectors.

I would be quite amazed if the 205 11r heads gave me a 100 horsepower increase. If they don't, I know a cam swap should do the trick after the heads and the right tune.

Maybe I'm being too hopeful.
 

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Discussion Starter #8
I’d be very curious to see what you do man! Different intake and 205s- your car would most certainly put down good power. I’m still impressed with all the stock bottom ended cars in the mid 300s


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My 331 puts 350/350 to the wheels AFR 185 Outlaw heads, TF intake, AFM cam, 9.5:1 compression, 1 5/8 long tubes, 2 1/2 exhaust. It's pretty tame IMO parts wise. I am sure it could take a full CR point more on pump gas everythign else the same. I am close to swappign to a SM-II intake and bigger exhaust. Will need a re-tune after that I'm sure.
 

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I am at a cross road with my build.

The motor is presently out and the block is bare, ready to be hot tanked.

Initial plans were to keep it simple stock bottom end, do some nice 190 TFS heads and a custom cam=done.

But now my mind has been going to doing a stroker.

How much more power does a 331 make over a 302 on average ? I know 350whp on a 302 with a proper cam and heads is possible.

Can a 331 crack 400whp?


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I was in your position not to long ago. I had considered a healthy HCI stock bottom end build. I have had two 347's.
I wanted to hit 400 rwhp and be done. I went the custom cam route with my 347's and was still unhappy. I'm limited on any build as it has to have great driveability and has to run on crappy 91 octane. That pretty much ruled out adding more static compression.
I started a thread on here and folks suggested a turbo build on a stock bottom end. I would have a basically stock car to drive in the city and when I want to have some fun; I just lean into it for a nice dose of boost that will reach my hp goal and more. I recently purchased a '94 GT with 53k original miles on it. The car is bone stock and unmolested. I'm installing a single turbo setup that cost me less than any of my stroker builds. I do not fear the factory block. If she blows; she blows. Many, many guys are doing exactly what I am doing with great success. It's nice to bolt on a hp adder without opening the factory long block.
It's just a thought to possibly help you in your decision. Good luck either way.
 

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I was in your position not to long ago. I had considered a healthy HCI stock bottom end build. I have had two 347's.
I wanted to hit 400 rwhp and be done. I went the custom cam route with my 347's and was still unhappy. I'm limited on any build as it has to have great driveability and has to run on crappy 91 octane. That pretty much ruled out adding more static compression.
I started a thread on here and folks suggested a turbo build on a stock bottom end. I would have a basically stock car to drive in the city and when I want to have some fun; I just lean into it for a nice dose of boost that will reach my hp goal and more. I recently purchased a '94 GT with 53k original miles on it. The car is bone stock and unmolested. I'm installing a single turbo setup that cost me less than any of my stroker builds. I do not fear the factory block. If she blows; she blows. Many, many guys are doing exactly what I am doing with great success. It's nice to bolt on a hp adder without opening the factory long block.
It's just a thought to possibly help you in your decision. Good luck either way.
What brand turbo set up are you going with? Is it custom and I wonder if it would be safe on my 331 stroker.
 

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What brand turbo set up are you going with? Is it custom and I wonder if it would be safe on my 331 stroker.
I purchased a used, custom kit so I can retain the AC. If you Google "On 3 Mustang videos", you'll see some nice videos of these inexpensive kits making sweet power. Fitment seems to be an issue with the inexpensive kits but it's probably a small price to pay for the added power.
 

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ill Give it to you straight.

Stock Block Stroker: you'll want to boost it.
Stoke Block Turbo: you'll want to stroke it.

Both of those scenarios require an aftermarket block. So step 1 for you is to get one.

If you think you Can't afford one or absolutely want to utilize your stock block then please just go with the on3 and leave EVERYTHING stock (even the heads). If you already have HCI then he only benefit to that is to have less psi to make the same power. That's it..

My brother and I put an on3 setup on his bone stock foxbody and made 512 on 12 psi on 93 octane and it Drove just like stock until lead foot. Sounds pretty badass huh? Well It drives like stock because the power comes in really late so in reality it's about as fast as a ported Eaton terminator. It's easy to get traction because of this as well which helps cars with limited suspension tweaks. Your going to hook with good street radials because at 3k rpm your not making any real power yet and by the time you get to your power-band you'll have physics on your side already.

Put a good rotating assembly or head cam intake combo on the stock block on3 and your going to regret it for many reasons. (Namely financially) So just leave it stock if you go with on3 as that is what their base level product is made for.





Also. Not sure if they have upgraded their clamps by now so prepare to buy aftermarket ones.
 

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ill Give it to you straight.

Stock Block Stroker: you'll want to boost it.
Stoke Block Turbo: you'll want to stroke it.

Both of those scenarios require an aftermarket block. So step 1 for you is to get one.

If you think you Can't afford one or absolutely want to utilize your stock block then please just go with the on3 and leave EVERYTHING stock (even the heads). If you already have HCI then he only benefit to that is to have less psi to make the same power. That's it..

My brother and I put an on3 setup on his bone stock foxbody and made 512 on 12 psi on 93 octane and it Drove just like stock until lead foot. Sounds pretty badass huh? Well It drives like stock because the power comes in really late so in reality it's about as fast as a ported Eaton terminator. It's easy to get traction because of this as well which helps cars with limited suspension tweaks. Your going to hook with good street radials because at 3k rpm your not making any real power yet and by the time you get to your power-band you'll have physics on your side already.

Put a good rotating assembly or head cam intake combo on the stock block on3 and your going to regret it for many reasons. (Namely financially) So just leave it stock if you go with on3 as that is what their base level product is made for.





Also. Not sure if they have upgraded their clamps by now so prepare to buy aftermarket ones.
Bad combo if it's coming in at 3k rpm. My Eaton supercharger came in at 3k on my Roush Blackjack. Of course; there are many factors involved.
 

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Your Eaton supercharger is a positive displacement roots style blower. Your powerband starts at idle fasterhangas, not 3k rpm.
 

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Your Eaton supercharger is a positive displacement roots style blower. Your powerband starts at idle fasterhangas, not 3k rpm.
Incorrect. It's exactly like I stated. Not all positive displacement setups make big boost off the line. Especially a mod motor. Throw a Kenne Bell on a 302 based 5.0 and it's a different story. Gobs of torque down low.
 

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Plain Jane, full acc, smog legal, with 9.5:1 comp: 340whp max. Otherwise, 10.5:1 cr, no smog stuff, no ac/ps and rev to 6500... you’ll see 400+.

went from 387 to 412 whp from a 302 to 331, same blower/pulley (12psi dropped to 8psi). That was with edel 60379 heads, explorer intake. 302 was stock short block and 331 was custom cam 224/232, .544/.544 and bumped cr down to 8.5:1. Since then, I’ve upgraded blower, rpm2, old design afr185 , 4” intake/maf, bigger tb. Going to add a t trim too. Shooting for 550-600whp. All of these changes and never failed CA smog.

If I did it again, I would’ve went 10:1 cr and full computer mod, with a diff computer and knock sensors: you’ll be able to tune it for boost & add meth inj with today’s better tuning solutions. Good luck.
 

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This thread is just wacky....
 

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I am at a cross road with my build.

The motor is presently out and the block is bare, ready to be hot tanked.

Initial plans were to keep it simple stock bottom end, do some nice 190 TFS heads and a custom cam=done.

But now my mind has been going to doing a stroker.

How much more power does a 331 make over a 302 on average ? I know 350whp on a 302 with a proper cam and heads is possible.

Can a 331 crack 400whp?


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Read post #45 He has a 347 making 422hp. Yes you can do it. I think you will need a cam about that size. Dyno Jet dyno and put a hard tire on the car for the test.

 

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ill Give it to you straight.

Stock Block Stroker: you'll want to boost it.
Stoke Block Turbo: you'll want to stroke it.

Both of those scenarios require an aftermarket block. So step 1 for you is to get one.

If you think you Can't afford one or absolutely want to utilize your stock block then please just go with the on3 and leave EVERYTHING stock (even the heads). If you already have HCI then he only benefit to that is to have less psi to make the same power. That's it..

My brother and I put an on3 setup on his bone stock foxbody and made 512 on 12 psi on 93 octane and it Drove just like stock until lead foot. Sounds pretty badass huh? Well It drives like stock because the power comes in really late so in reality it's about as fast as a ported Eaton terminator. It's easy to get traction because of this as well which helps cars with limited suspension tweaks. Your going to hook with good street radials because at 3k rpm your not making any real power yet and by the time you get to your power-band you'll have physics on your side already.

Put a good rotating assembly or head cam intake combo on the stock block on3 and your going to regret it for many reasons. (Namely financially) So just leave it stock if you go with on3 as that is what their base level product is made for.





Also. Not sure if they have upgraded their clamps by now so prepare to buy aftermarket ones.
That’s a good point!
 
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