351 Build What Kind Of Power Am I Looking At

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Nate87

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#1

• Dec 7, 2015

• #1

In the process of building up a 72 351w block, I have kb flat tops(w 2 reliefs) stock crank/rods, comp double roller, and xe268h cam, ported dooe heads, comp calculator says 10.3:1. Not looking to make a race car just a fun car to take to the strip once in a while. Any body run a similar combo or have any idea what this will make for power? I'm thinking 270ish rwhp is that way off? Thanks

 

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Nate87

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#2

• Dec 7, 2015

• #2

Also edelbrock performer intake and performer 600 carb

 

A5literMan

At least it is lumpy...

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#3

• Dec 7, 2015

• #3

My guess is your guess is a close guess

 

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Nate87

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#4

• Dec 7, 2015

• #4

Not so bad for 70's iron I suppose, so a decent improvement over pretty much stock 5.0. Any idea 1/4 mile times? 88 lx hatch, 5-speed, 3.55 rear, 9" slicks?

 

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Nate87

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#5

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Also any suggestions on head gaskets would be appreciated, I ran 9333pt1's on the 5.0 with arp bolts, seemed to work well, are these pretty trustworthy on decent comp na engines?

 

A5literMan

At least it is lumpy...

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#6

• Dec 7, 2015

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Yes the felpro's are what I would use. As far as times goes...there's a lot of variables but I'd say you could see 12's to low 13's.

 

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Nate87

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#7

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• #7

I'd be pretty happy with a high 12 run. Just trying to get a feel for how it would stack up to the stocker. Got about 5 months till the track opens in NH so I guess I'll be anxious to find out until then lol. Thanks for the replies

 

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89stang1

Stroked and Juiced

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#8

• Dec 8, 2015

• #8

Nate87 said:

I'd be pretty happy with a high 12 run. Just trying to get a feel for how it would stack up to the stocker. Got about 5 months till the track opens in NH so I guess I'll be anxious to find out until then lol. Thanks for the replies

Click to expand...

It will blow away a stocker, you should have no problem making over 300rwhp and better torque. Stroke that beotch get some good heads and you could be easily over 400rwhp

 

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Nate87

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Dec 8, 2015

#9

• Dec 8, 2015

• #9

Thought about stroking it, crank was cut already and mint, so went with a flat top .040 over. As for heads, a set of afrs would be awesome but not in the budget unfortunately. What's the real story with pro comps, or flo tek heads? Are they really crap or good enough for a mostly street car? I've heard so many mixed reviews on them but no one really running them to back it up.

 

89stang1

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#10

• Dec 8, 2015

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Nate87 said:

Thought about stroking it, crank was cut already and mint, so went with a flat top .040 over. As for heads, a set of afrs would be awesome but not in the budget unfortunately. What's the real story with pro comps, or flo tek heads? Are they really crap or good enough for a mostly street car? I've heard so many mixed reviews on them but no one really running them to back it up.

Click to expand...

id rather have trick flow or afr but if you already have those heads and your at the end of your budget they will be fine, 10.3:1 comp should give you a little extra hp i still think you should make over 300rwhp imo

 

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Nate87

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#11

• Dec 8, 2015

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300 sounds pretty healthy, I have the dooe's but they will need some machine work, guide plates, screw in studs, hardened exhaust seats etc.. My machinery est prob 500$ or so, so I'm trying to weight my options. Dooe ported, take a chance on cheaper alum heads, or save up and go for the good stuff. Like I said it'll be a mostly street car, track maybe 3-4 times a year, so tough to justify 1400 or so on heads lol. Very tempting though at the thought of the power over the irons. Thoughts? Suggestions?

 

89stang1

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#12

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I would save up stroke it 393 or bigger get afr or trickflow heads maybe find a used set in really good shape. In the end your compression will keep you NA and i bet ya within a year or two you would end up doing the mods i say anyway. My only regret with my stroker is not stroking a 351 instead of a 302 i love the raw 450rwhp plus hp and massive torque numbers they make just hearing them start excites me. I love the RELIABILITY of a nasty big ci NA motor thats just me and thats your best route imho. good luck either way your gonna have fun

 

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Nate87

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#13

• Dec 8, 2015

• #13

Thanks man, def agree, big block cubes in small block trim is badass, things rev lightning quick. I already have new .040 pistons, already fitted to rods, so stroker is out, but possibly gonna save up for heads that will support the bigger cubes, and maybe next year a stroker bottom end. Even at .040 I'm at 359 so 57 cubes more than I had lol. Thanks for the replies, dying to drive this sucker! Spring is so far away!

 

stykthyn

I want to measure mine. It doesn't look that tall.

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#14

• Dec 8, 2015

• #14

Man if you HAVE to put money in the heads save some extra scratch and get a set of aluminums that will let that engine BREATHE. Even budget aluminum heads will outflow those dooe's after port work.

My biggest regret was not going as large as possible on my heads. It's on a 302, but the large head debate still applies here as well.

 

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Nate87

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#15

• Dec 8, 2015

• #15

Think that'll end up being my best bet, go as big as I can afford, that way I'm set for heads when/if I eventually build a stroker

 

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joetrainer31

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Dec 10, 2015

#16

• Dec 10, 2015

• #16

Nate87 said:

In the process of building up a 72 351w block, I have kb flat tops(w 2 reliefs) stock crank/rods, comp double roller, and xe268h cam, ported dooe heads, comp calculator says 10.3:1. Not looking to make a race car just a fun car to take to the strip once in a while. Any body run a similar combo or have any idea what this will make for power? I'm thinking 270ish rwhp is that way off? Thanks

Click to expand...

minimum 30-50hp, 50-70lbs torque

 

N

Nate87

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Dec 28, 2015

#17

• Dec 28, 2015

• #17

Figured I'd revive this thread with an update and couple more questions. Ended up picking up a set of used(in great shape) old j302 ford Motorsport heads, for the same 351. Comp will remain the same around 10.3:1. My questions are what size carb would be ideal? And what are your opinions on head gaskets for the alum heads? Thanks in advance! Also this engine is going in an 89 crown vic, police interceptor, I did a t5 swap to, about 3700lb, instead of the 88 lx hatch if that will help with the carb choice.

 

A5literMan

At least it is lumpy...

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#18

• Dec 28, 2015

• #18

A 351 with a max rpm of 6k would use around 625cfm. If you're going to use more rpm and a vacuum secondary carb you could increase that to around 650-700(max). Id probably use a 600-650. My last carbureted car was a Chevy small block 331-with solid lifter cam-6200 shift point and loved a Holley 650 double pumper. Car ran mid 13's at over 100mph on street radials(woeful 60ft times lol)

 

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Nate87

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Dec 29, 2015

#19

• Dec 29, 2015

• #19

That sounds pretty good, comp rates that cam for a powerband of 16-5600 so I won't be going to 6 even. Guess I'm going with a 600, thanks. Any head gasket ideas for the alum heads? Can you run basic(not exactly sure part #) 8554pt2's with a decent comp ratio?

 

A5literMan

At least it is lumpy...

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#20

• Dec 29, 2015

• #20

Get fel pro 9333