408 stroker build?

Kind of a tall order, what are your overall driving plans? I see "pro street", does that include high way miles? What over drive transmissions are you looking at? Manual, or auto?
Are you using a Cleveland block?

for an intake, i would go with the victor jr for the HP level you are looking for. for a carb you want at least 750xfm 850 is better. for headers you want big primary tubes on the order of 1 3/4" going into a collector of at least 3 1/2".

its possible to make 650 on pump gas with a 408. but its going to take a serious combination and some rpm. something like a ported super victor, some $2800 heads, a solid roller. as far as carb if you are looking for all out HP an 850 venturi size would probably be the choice, but it would probably go faster at the track with the smaller 750/950 venturi size. you will probably need a dished piston unless you are willing to run race gas, but race gas would make your goal easier.

Unless mostly street, the 750 wouldn't be my first choice for a carb as I saw a nice gain at the track when I switched from a Biggs 750HP to the 950HP in my 10.6:1 compression 393w with a Vic Jr.

the 950 has the same 1.375"venturi size of a 750. some 750s that have been cnc'd .050 actually have a bigger venturi (which is the minimum area) than an OOTB 950 HP body. the 850 is the big 4150 venturi at 1.5625". we actually picked up .4 in the 1/8 mile going from two holleys (an HP 750 (1.375" venturis) and holley 830 (1.5625" venturi)) that both ran 7.20s to an AED 750 HO modified which has a 1.425" venturi that ran 6.80s. the 830 has the larger 850 main body/venturi size. even at a given flow rate carbs and metering can be very different.

I have a pro built HP 750 used only for dyno tuning. Proved slightly to big for my 347. It made 470 HP. I would think it would be perfect for a 408 with some street manors. That would be my first choice on a build like yours. Bigger if track only use but not if you ever want to stree the car. PM me if interested

That is a tall order as I think of it. About the best 347 if ever heard of made 520 HP on pump gas and it had very hairy street manors. If you do the math on that it would come out about 611 HP for a 408 but not very streetable. I would aim for around 525 HP and have a very fast car that is fun to drive. Much easier to get. Use a 225 cc AFR head or similar, Vic jr or Parker funnel web. 9.5 CR and contact a cam grinder for the cam needed to get you there. You will be a lot happier in the end unless track use is you only plan.

I agree with the generality stated previously that this is a lot of power from 408 cubes. I think you want at a minimum 10.5:1 compression (pump gas 93 octane possible with the right cam) and you'd be better off with ~13.5:1 or more compression and run E85. I'm not going to pretend to be an expert on E85. You need about 30% more fuel than gasoline so you'll need a carb specifically for it. You'll want heads with at least 220 intake port volume and the intake should probably be ported by a pro to match. You'll need a very free-flowing exhaust system. Also the heads should probably get some work to optimize your results. This will be a high rpm build so you will need a cam to match - probably a solid roller.

Since your goals are so ambitious I think the best thing for you to do rather than rely on "internet experts", go to an engine builder that does this for a living and have him spec out everything matching to get the most out of your combination. Otherwise be prepared to spend time researching options. Be prepared that the E85 mix varies at different times during the year. If I were doing an E85 build I would probably buy fuel in drums and test it before using. If you fill at the pump and get some fuel that's light on ethanol you could destroy your investment with detonation.

On edit: you said the block is from a Torino but you didn't say what this is going into. If you are putting this engine into a Mustang the body will need significant reeinforcement to prevent it from twisting into a pretzel. You want your doors to open and close right - make sure you make adequate preparations.

If I wanted 650-700 HP for a street car naturally aspirated I would probably go with a 385 series stroked to the most cubes possible. Jon Kaase Boss 9 comes to mind!

http://www.jonkaaseracingengines.co...-custom-built-boss-nine-and-p-51-engines.html

Or you could buy a dry sump Nascar motor and detune it. They make ~800 HP at 9,000 RPM. Looks like this engine meets your goals between 6,000 and 7,000 RPM somewhere. Of course most people would not want to buy racing fuel and put up with a racing motor in their street car.

http://www.toonutsracing.com/smf/index.php?topic=928.0

I was just at Hendricks Motor sports and got the behind the scenes shop tour. ( I sell Haas equipment and Hendrick supplies Stewart Haas racing with motors). A full on NASCAR engine goes out the door at $80,000. I heard that from the man first hand. They are designed to last 500 miles between rebuilds. Not what I would put in a street car. That said, the kind of power he OP is looking for will not come cheap no matter how you get it. The car it ends up in will need. To be well built as well. Handling that kind of power takes a lot of modifications to every aspect of a car. As to the twisting a mustang up comment. I had a 65 back in the 70's that I drag raced. The motor was a 289 stock except F4b intake 650 holley, solid lifter 289 HP cam and headers. It was a 4 speed car and I had slicks and 4:57 gear in it. That motor made 300 HP if it was lucky, 260-270 more likely. But it was a light car and with the slicks and deep gears it hooked well. Ran 12.80s. After about 4 track weekends both the rear quarters had creases in them from the stress right in front of the wheel wells. I can only imagine what 600hp would do with out a full cage and frame mods

65FBE2 said:

I was just at Hendricks Motor sports and got the behind the scenes shop tour. ( I sell Haas equipment and Hendrick supplies Stewart Haas racing with motors). A full on NASCAR engine goes out the door at $80,000. I heard that from the man first hand. They are designed to last 500 miles between rebuilds. Not what I would put in a street car. That said, the kind of power he OP is looking for will not come cheap no matter how you get it. The car it ends up in will need. To be well built as well. Handling that kind of power takes a lot of modifications to every aspect of a car. As to the twisting a mustang up comment. I had a 65 back in the 70's that I drag raced. The motor was a 289 stock except F4b intake 650 holley, solid lifter 289 HP cam and headers. It was a 4 speed car and I had slicks and 4:57 gear in it. That motor made 300 HP if it was lucky, 260-270 more likely. But it was a light car and with the slicks and deep gears it hooked well. Ran 12.80s. After about 4 track weekends both the rear quarters had creases in them from the stress right in front of the wheel wells. I can only imagine what 600hp would do with out a full cage and frame mods

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Yeah they are cheaper used but still way too rich for my blood! And detuned is the right word, but probably doesn't adequately convey what detuning is... change almost everything in the motor to make it streetable. The advice was also somewhat tongue in cheek - trying to convey to the original poster how much power he's really talking about. If I were really trying to make that much power it would be a turbo build. I'm not so certain a stock 351W block will really even hold up to that much NA power for long. That's where the expert comes in. A big bore Dart with 454 cubes and the right choice of components may get him to his goal without much trouble if he really wants to stay with the 351W size motor.

I'm not surprised you got creases in the quarters. I suppose you could have 600 hp and run space saver spares and never cause a problem with the body, but when you start hooking the tires everything changes. I remember a friend in high school with a 440 in a '70 Dart - wicked fast car, but there was some bondo in the rear quarter that fell out after a few trips to the strip.

Agree that the car needs to be prepped for the expected HP. I also agree that a built 429/460 will easily make the desired HP and not be maxed out.

A set of welded subframe connectors and other similar chassis strengthening tricks are needed to help maintain the body integrity. With only subframe connectors, export brace, and an 8 point roll bar, for over 5 years I have raced a 500hp 393w and a 4 speed week after week and have yet to experience any issues in body integrity. 26x10 slicks, 5K launches, 1.5xx wheel standing 60's giving low 11 second runs in my heavy street car.

@ Dennis112 The 8 point cage and frame connectors make a huge differance. That thing looks straight as an arrow. 4 speed and all! Looks like it would be a ton of fun to race. Do you bracket race it? If so how well do you do against the automatic cars? We have a guy around here with a 65 Falcon Sprint running a 4 speed and he does just fine. Might win a few more races with a a C4 but he refuses to give up the fun factor of the toploader. I love it.

65FBE2 said:

@ Dennis112 The 8 point cage and frame connectors make a huge differance. That thing looks straight as an arrow. 4 speed and all! Looks like it would be a ton of fun to race. Do you bracket race it? If so how well do you do against the automatic cars? We have a guy around here with a 65 Falcon Sprint running a 4 speed and he does just fine. Might win a few more races with a a C4 but he refuses to give up the fun factor of the toploader. I love it.

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Thank You.

I run in a dedicated bracket racing stick class, both at my home track (Beaver Springs Dragway) and when touring with the Prostick Racing group. I rarely race the slushbox's but have held my own as this car comes on hard on the top end when it is least expected. The car and I were stick class champions in 2010 with 200+ runs that year.

I agree with your Falcon Sprint guy--a manual transmission increases the fun factor and, for me, is the only way I roll.