build me a stump puller

[shortymac83]

Since I'm going to be completely restoring this truck, I figure, why not go with a hot motor to give it something a bit different? I want to keep the 250 in there, but I'd like to see 200 RWHP and over 300 lb-ft. is this unreasonable for a street motor? I'd like to see the torque as low as possible. Granted, it won't be a daily driver, but I'd like to be able to get it on the highway and see 2500-3000 miles a year on this. Just for the heck of it, let's put a ceiling of $5,000 on this. Stock block and crank would be preferable, but the sky's the limit when it comes to camshafts and compression. Granted, it'll have a 4bbl carb and long tube headers, but I don't know what kind of cam or what kind of compression it should use. Also, if it's going to be built like this, what kind of electric ignition should I use? I'd like to use a quadrajet for the carb, with a 1" tall adapter on a squarebore offy intake. The reason for the qjet is its efficient fuel metering coupled to the HUGE secondaries and balls out 750 cfm performance.

A bit about the vehicle overall: truck is a 67 C10 with no options, so vacuum is not an issue, nor is any accessory driven stuff, because PS isn't there to worry about. Exhaust will be straight pipes with no mufflers. If it DOES have muffs, it'll be getting either bassani or flowmaster mufflers. Transmission will be a 3 speed manual, and the rearend will be the stock 10 bolt with 3.08 or 3.23 gears. This truck needs to be able to be cold started in the winter (should we ever need to move it), and it should be able to idle all day in traffic at under 200*.

This is a very long term project (the body and suspension is getting done first, then the motor), but I want to get something on paper so I have a plan and can start collecting parts now.

[70 shorty]

Well, mine is a 250 with a Clifford intake, Holley 390, RV cam, header and hogged out cylinder head. It's also a 3spd on the floor with a 3.73 rear. I'll let you know how it runs when I get it sorted out. I just got it running good enough to move under it's own power today and now need to get it sorted through so it runs good.

[shortymac83]

how big is your cam?

[shortymac83]

oh yeah, and before I forget, how much power can a 3 on the tree take in stock form?

[70 shorty]

Shorty, I don't know many specifics on anything on the engine. My uncle built it when it was his truck. All I know is he told me it was a mild cam. I still need to find out what kind of compression it's running, I do know he built it as a street truck, it was supposed to be my cousin's high school and college ride.

[Tx Firefighter]

If you want bottom end torque, spend a few hundred bucks to get a 292 to start with. That way you still get your inline 6 fix. The 292 is a torque monster. I have one that came out of a dump truck. The guy used to drive the dump truck loaded with dirt, and pull a backhoe with it. That's plenty of torque there.

[68w/sbc406]

i agree, start out with a 292

[shortymac83]

I think I"m being misunderstood here...


Once done, this truck isn't doing any work. It's just going to be a nice street/show truck, and it would be nice to be able to do a burnout every once in a while, and to be able to keep up with traffic with 3.08 gears over 70 mph. I don't need a 292 for that.

[Palf70Step]

Yeah I misunderstood when first reading it also. Didn't think you were going to pull nothing with a 3:08. I may be looking at doing my 250 up in the future, but I do know it'll cost you a fair bit more than building a small block, but it is different and a built striaght six has a wicked sound to it!!

[Tx Firefighter]

Hey man, you said, "Build me a stump puller" and "I'd like to see the torque as low as possible". All that equates to a 292.

Pistons, cams, intakes and exhausts all cost the same for the 292. The only difference is buying a 292 core to start with. A hot 250 will still pale compared to a 292.

You need to buy Leo Santucci's book on hot rodding 6 cylinders. It's well worth the money.

[4x4Poet]

Originally Posted by shortymac83

...I want to keep the 250 in there, but I'd like to see 200 RWHP and over 300 lb-ft. is this unreasonable for a street motor? I'd like to see the torque as low as possible....let's put a ceiling of $5,000 on this. Stock block and crank would be preferable, but the sky's the limit when it comes to camshafts and compression. Granted, it'll have a 4bbl carb and long tube headers, but I don't know what kind of cam or what kind of compression it should use....I'd like to use a quadrajet for the carb, with a 1" tall adapter on a squarebore offy intake. The reason for the qjet is its efficient fuel metering coupled to the HUGE secondaries and balls out 750 cfm performance.

...Exhaust will be straight pipes with no mufflers. If it DOES have muffs, it'll be getting either bassani or flowmaster mufflers....

Yeah, you did make a boo boo saying "stump puller" when you aren't starting with enough CIs. No biggie. Going for low-rpm peak torque is still a good idea.

One of America's 6-cylinder experts is Clifford Performance in Temecula, CA (SoCal). Clifford specializes in wringing power out of 6-cylinders. Clifford has reworked countless sixes into far stronger engines than stock. They do it mostly with porting, bigger valves, higher compression, better intakes, and headers all matched well and packaged with balancing and blueprinting to protect high rpm use. Clifford can fuel inject some sixes. Click on "engine parts," then "Chevy," then "250." You definately need their catalog.

For muffs, I recommend SpinTech Mufflers. They are all-welded 3/16" plate with internal "spin traps" that create a vortex with a venturi effect that scavanges the gases out the other end. They have solved the age-old problem of needing low back-pressure with quiet sound. They have quiet street muffs, performance muffs, and also sub-90db full-on race muffs that perform better than straight pipes. Can't say enough about them until you see the price tag. Available in SS and aluminized.

[shortymac83]

I'll use clifford only as a last resort. I'll be damned if I pay their prices, they're almost as bad as Mondello and Olds Performance Products. "here, buy these AC spark plugs at $25 a piece, because we sell them." I got plenty of power out of our 258 AMC just with head porting, 9.5:1 compression and a quadrajet sitting on an offy 4bbl squarebore intake that I got at a swap meet for $50. Go to clifford, it'd be $1500 or more for all that crap. no thanks.


and if the old man can get 13's out of a 4 door 62 bel air with a 10:1 compression 235 with a 3/4 race cam, a 3 on the tree and 4.11's in the rearend, I think I can get my goal with this motor.


my main question is (and always was) - what camshaft will get me 200 hp and 250-300 lb-ft torque with 9.5:1 compression, port and polish on the stock head and a .060 overbore breathing through a 750 cfm quadrajet with a 1" spacer?

[browndawg71]

Sounds like you want a tow truck one minute and a dragster the next. scrap the sixes and throw in a 454. that way you will have both.

[shortymac83]

I don't want either. I want a truck that is fast enough to keep up with a ricer (say, 16's) and be able to stay at 70 mph on the highway without worrying about the wind resistance from a brick of a frontend.


and if I go with a V8, it'll get an olds 425.

[Tx Firefighter]

Originally Posted by browndawg71

Sounds like you want a tow truck one minute and a dragster the next. scrap the sixes and throw in a 454. that way you will have both.

What kind of a homo runs a 454?

(it's a joke people, he bought my 454 short bed about a month ago, I'm just hacking on him)

[browndawg71]

the same kind of homo that runs cummins turbo diesels!!!

[67ChevyRedneck]

Don't go gettin upset at me....but if you want 300hp and 300 ft-lb of torque the quickest and cheapest thing to do is search your local swap sheet for a rebuilt 350...around here they go from $700-$1500 and slap in a cam...that's all you would need to do for that kind of power. Plus, I HAVE smoked rice burners with a 350, 700R4, and 3.73 rearend, 15mpg, AND my truck will EASILY cruise at 80mph, @2400rpm and PASS traffic. I topped her out one day at 109....damned rear-end is too low......just my .02 cents bro.... seems like a lot of work and too much money to put into a six..... I had a stock 250 I-6 in my truck and I could easily smoke the tires. I'd say leave her alone or get a V-8..... "you can't have a tow truck and a drag car"

[shortymac83]

the thing with these trucks is that EVERYONE goes with a V8. I'd like to try something a bit different, and still have some power. Hell, maybe not even "some" power, but interstate cruising would be nice. like I said, if I go with a V8, it's getting a .030 over olds 425, and T5 transmission.

[71cadc10]

If your goal is to be different and have torque, I'd go the v-8 Olds route. With the grunt of the 425 you can run a highway friendly gear 2.7-3 and still have get up and go, and run an inexpensive TH400 setup. That motor will make torque from 2000 on so you can run a nice tight converter, and motor around happily on the street.

that's my v8 biased $.02

[shortymac83]

Let's rephrase this again,


What camshaft should I use in my 250 with a 4 bbl carb, .030 bore, 9.5:1 compression and headers? Rearend is 3.08 posi and the tranny will be a 3 spd manual. Tires are 28" tall, and it will not be hauling anything but my fat butt around.

If this doesn't work, I'll just give up and call FCR.

[Tx Firefighter]

post your questions over at www.inliners.org for more 6 cylinder dudes to answer. They have a forum board too.

[jeffnstef]

Might "Stump Puller" be a double meaning for something else !

[Palf70Step]

Shortymac
her is a good article about a be different 6 build. I am sort of using it as a basis for what I want to do with my 70.
http://www.truckworld.com/How-To-Tec...vy-engine.html

One thing, if you are going to tear into the engine to do alot of this, you mihght want to do what that guy did (and TX Firefighter said) is start your rebuild with a 292 block. That extra bit of cubes and the low end the 292 provides makes a BIG difference.

Be different and good luck.

"Keep em Inline!"

[4x4Poet]

I'm with you, shortymac83, stick with the six. I prefer sixes in both gas and diesel versions for trucks. Preferably big sixes.

Looks like no one here knows which cam for you application. BTW, won't a cam maker have the info you need? Just curious.