638 cid Big Block in a 69 CST/10 Shortbed

[bhunt31]

I'm wanting to build a Big Block for my 69 CST/10 and badge everything up like a 396 to fool the untrained eye. I'm looking at a Dart Big M block that is capable of 4.625" bore and 4.75" stroke. I'm wanting to keep a mild cam in it and iron heads so it runs and looks close to a stock engine. Preliminary runs on my Dyno program comes up with around 750lb-ft of tq@2K RPM and 502hp@4500RPM. The question I have is: has anyone done anything close to this power range in one of these pickups and what has to be done in ways of rear end, transmission,...etc. to handle this kind of power? Also, if anyone has any parts suggestions to stuff in this engine, please advise, remember I want to keep it stock appearing and idling.

[weasel29gm]

Why? Thats alot for the street nothin' wrong with a BB but you can go to much with one.

[bhunt31]

mostly bragging rights, and I want to go with something that noone else has, I know it's a lot, which is why I want to keep it tame in the cam. There's too many crate 572s being dropped in everything these days, I want something different, something that's as custom as the rest of the truck is going to be. It's not meant to be a street racer and I know I'll never be able to hook it up on the street, but I might get up the nerve to take it to the strip every now and then, to quote the infamous Carrol Shelby "Too much Horsepower is just enough" =)

[Farmtruck71]

i have a 502 in my truck and it made close to 700 hp to the back wheels and i havent had a problem with anything other than killing the tires when it leaves,and it has been 10.11@130mph weighing 4050. I also have a dart big m block,it's brand new still in box,it has billet splayed main caps

[bhunt31]

Originally Posted by Farmtruck71

i have a 502 in my truck and it made close to 700 hp to the back wheels and i havent had a problem with anything other than killing the tires when it leaves,and it has been 10.11@130mph weighing 4050. I also have a dart big m block,it's brand new still in box,it has billet splayed main caps

Wow, that's a lot of horses to the back wheels. That's the block I'm looking at, so you're running the stock rear end, gears, and suspension and it holds it? What kind of tranny are you running? Does your 502 idle smooth or not? How does it get around on the street, like from stoplights and such during normal driving? I want to be able to drive the thing, I just want the "impressive factor" there when I need it. I live in a small town and people around here are scared to death of anything that has a big block in it, let alone a 638cid Big Block, so it'd be the top dog around here when I get it built.

[Farmtruck71]

Originally Posted by bhunt31

Wow, that's a lot of horses to the back wheels. That's the block I'm looking at, so you're running the stock rear end, gears, and suspension and it holds it? What kind of tranny are you running? Does your 502 idle smooth or not? How does it get around on the street, like from stoplights and such during normal driving? I want to be able to drive the thing, I just want the "impressive factor" there when I need it. I live in a small town and people around here are scared to death of anything that has a big block in it, let alone a 638cid Big Block, so it'd be the top dog around here when I get it built.

when it made that hp number it had a 275 shot, it now has a 350 shot going through the NOS Big Shot plate. The rearend is the stock 12bolt with a detroit locker,3.73. gears,stock axles,and i run 29.5x10.5"S" slick. The tranny is a turbo 350 with a full manual valve body,4" race pan, and a Neal Chance bolt 2gether convertor. As far as how it idles, it idles good,very crisp,clean sounding,and the cam is around 700 lift with the 1.8 Jesel shaft mounted rocker arms thats on it. My truck is pump gas friendly, last summer i used to drive it all the time around town, going to cruise nights, its a blast to see the look on peoples faces when you pull up behind them in traffic and their rear view mirror is shaking.
Here is a short vid
http://videos.streetfire.net/search/...5b88d75b10.htm

[bhunt31]

That truck is just crazy man, I hope mine runs that good when it's done. Thanks for all the technical advice guys, I've never really had experience with hp numbers that high before in a truck, so I wasn't sure what it was gonna take, so now I have a better understanding, THANKS EVERYBODY! I will start a build thread for my 69 Shortbed when I start on the restoration(as soon as it gets warm outside, haha)

[bhunt31]

Originally Posted by Farmtruck71

when it made that hp number it had a 275 shot, it now has a 350 shot going through the NOS Big Shot plate. The rearend is the stock 12bolt with a detroit locker,3.73. gears,stock axles,and i run 29.5x10.5"S" slick. The tranny is a turbo 350 with a full manual valve body,4" race pan, and a Neal Chance bolt 2gether convertor. As far as how it idles, it idles good,very crisp,clean sounding,and the cam is around 700 lift with the 1.8 Jesel shaft mounted rocker arms thats on it. My truck is pump gas friendly, last summer i used to drive it all the time around town, going to cruise nights, its a blast to see the look on peoples faces when you pull up behind them in traffic and their rear view mirror is shaking.
Here is a short vid
http://videos.streetfire.net/search/...5b88d75b10.htm

That's crazy man, looks like you went against a beast of a camaro. Who cares though, right? You still ran 10s!!! That's just awesome, I love to see them old trucks show the new age cars they can still run with the best of them.

[Farmtruck71]

Originally Posted by bhunt31

That's crazy man, looks like you went against a beast of a camaro. Who cares though, right? You still ran 10s!!! That's just awesome, I love to see them old trucks show the new age cars they can still run with the best of them.

The guy in the camaro is a friend of mine so we raced for the fun of it.The camaro has been to the PGD's(pump gas drags) before and placed in the top 5, it has run 8.80's on BFG Radials with the power coming from a all aluminum 632ci and a glide. Thaty night i think my truck went 10.22@129

[special-K]

Somrthing cool about an old truck with way more power than you "need."
In a simular subject.I bought a truck a while back that was an origunal big block truck,still very original.I restored it all original but used an LS6 crate motor using all the 402 stuff on top and painted everything factory colors and used factory stickers.It was powerful,reliable,yet I showed it as original.

[powell72]

I can't imagine anything rearend or suspension wise would break until you try to make it hook up. As long as the tires are the weakest link you SHOULD be o.k.

[beater69]

Originally Posted by powell72

I can't imagine anything rearend or suspension wise would break until you try to make it hook up. As long as the tires are the weakest link you SHOULD be o.k.

exactly what i was thinking. if you go and put a big set of slicks on the back or put a lot of weight out back you could have some issues. I do agree with carol shelby though but we are talking about enough money to buy a small third-world country

[bhunt31]

Originally Posted by beater69

exactly what i was thinking. if you go and put a big set of slicks on the back or put a lot of weight out back you could have some issues. I do agree with carol shelby though but we are talking about enough money to buy a small third-world country

Yeah, I'm not wanting to tub it all the way, but a little would be ok and yeah, it's enough money to buy a small 3rd world country, but the only starving person I'm gonna have to worry about while I'm building it, is me,

[mnunn454]

Gotta love those BBC SWB C-10's. You're singing the song I love to hear.

No experience with an engine that big, but (but I'd love to). One thought though. Due to the "swept volume" of the cylinders that have to be filled, what would notmally be a very radical cam on a smaller engine would be tamer on a huge engine like the 638. So, don't underestimate how much cam it needs to even be "tame". Talk to the cam experts with your requirements.

Regarding the anticipated performance, please let us know if you'll be using a neck brace or high back bucket seats.

Thanks.

[rage'nrat638]

hello heres a picture
dart big block 638 ci 10:1 comp $20,000 engine

clink the link in my signature thats what one sounds like

[Bishops Trucks]

Originally Posted by rage'nrat638

hello heres a picture
dart big block 638 ci 10:1 comp $20,000 engine

clink the link in my signature thats what one sounds like

Damn, that rat sounds great.

[mnunn454]

Originally Posted by rage'nrat638

hello heres a picture
dart big block 638 ci 10:1 comp $20,000 engine

clink the link in my signature thats what one sounds like

Yeah. That'll sure pass for a 396.

[bhunt31]

Originally Posted by mnunn454

Yeah. That'll sure pass for a 396.

well, I'm not going that crazy with it. I'm gonna have iron heads, mild cam, and decently quiet exhaust on mine. I can't go that crazy with it, I'd kill myself first time out. I'm gonna "stock it out" though. It's gonna be a cruiser, a Saturday night bragger. To the untrained eye with all the 396 badges and mild cam, iron heads, quiet exhaust, and aluminum intake; I can pass it off as a 396. I dunno, haven't made the final decision on whether I wanna put it out there and let the world know that I got the big Dog under the hood or not...still thinking...

[ThatOneBlue67]

Wow, that 638 is coming to eat people! That thing sounds like a beast.

I believe someone said "Everybody is dropping in a 572 these days, I want to do something different."

Well, I admire your drive to go larger, but I know I sure as Hell don't have a 572! I wish! So... hook a brotha' up if you have any lying around.

[bhunt31]

Now you've gone and done it. Now I'm gonna have to have the smile surgically removed from my face after hearing and seeing that 638. As for the 572 comment, I'm just saying that the 572 is a very popular custom vehicle engine these days, I don't want anything about this truck to be the "norm" It's easy to say, "I've got a 572 crate engine in there", lots of custom car builders choose that engine, and I'm not saying it's a bad engine, cuz I love the 572, I'm just saying that it's cooler to push it to the limit and say "it's a 638 cubic inch Big Block that I built in my garage" But at the same time, badge it up as a normal 396 so the untrained eye won't know what it really is.

[67chev"BIG-Bertha"]

Yeah hook me up with a 572 too. Just teasin, even though copperhead had one in it and look at it, i would still rather have your 638 I mean wowwwwwwwwwwwwww.

[bhunt31]

Originally Posted by 67chev"BIG-Bertha"

Yeah hook me up with a 572 too. Just teasin, even though copperhead had one in it and look at it, i would still rather have your 638 I mean wowwwwwwwwwwwwww.

I'll build you one, or I got catalogs you can order a 572 from...lol. No, seriously, 572's are awesome, they are a monster of an engine. My thing is, pick up the last 5 copies of Super Chevy or one of those mags and flip through and look how many 572s are out there these days, a lot of people have them, you don't see too many 638s though. I guess cuz they don't make a 638 crate, but I think the engine should be just as much your creation as your custom vehicle is, if you do all that work to the body and chassis, why would you want to drop in a "Kit-in-a-box" engine? Shouldn't it be as much built by your hands as the vehicle it's going in?

[kenm78]

Good luck on your project!!! hope you don't break your pocket book on it

[rage'nrat638]

get ready to spend some cash i spent $10,000 fixing stuff i broke

[bhunt31]

What all did you break with that engine? Have you ever had it on a dyno to see how much it puts out? As for breaking my budget...yeah, it's gonna be a while, I'm gonna do a close to stock 350 or a nice 500hp 406cid SBC for now and do the body and interior up, then we'll start on the dragon's breath under the hood. Maybe that's what I'll name the truck "Dragon's Breath" Lay down a black basecoat, then spray green glitter paint lightly over the top, then seal it all with a good covering of clearcoat. Then I'll have to have the thunder under the hood,