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eat a beaver, save a tree
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is the 350 thats in it now an olds 350 or a chevy 350? if it's a chevy it won't work. you'll have to chance the frame mounts (maybe have to make a set, or get a set ot of a junked car & weld them in). a 403 olds is a great torque motor, & i like the hell out of them. if the 350 thats in it now is a chevy, just drop a 400 small block right in. they put out the torque too.

i've seen a 455 olds in a 72 short bed, & i think he used a set of car mounts to get it in there.
 

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Discussion Starter · #3 ·
403 to 350

It's a chevy 350, it does appear the mounts are further up in the engine. Now that I know what to expect I won't be too surprised. I got the motor at a great deal so I don't mind a little work installing mounts. I take the 403 mounts off the doner car and weld them on my Suburban. Looks like the headers may be a bear to get in there also. Thanks for the heads up.
 

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I would stick with the small block. You`ll have a better chance of making power with it than the 403. The 403 isn`t known as a performance engine, they`re known for being weak in the lifter valley due to it being webbed. a stock 403 is putting out about the same power as a stock 350, only the 350 is easy to modify and get parts for, so unless you`re just looking to do the swap out of being different, or just for wanting to, then I wouldn`t waste my time on a olds 403, I`d go with a 455.
 

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eat a beaver, save a tree
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DoubleVision i totally disagree with you on that one. i had one out of a 79 or 80 station wagon, & it had a heck of a lot more torque than any other stock chevy 350 i've ever ridden in. i could be rolling at about 30 mph & pull it back in second & floor it & it would jump side ways from spinning (2.73 gears). i've never had a stock 350 with that much torque. from what all i've seen & heard they are known to break in the main webbing, not the lifter valley, but only seen that happen in a hi performance 403. the first year of the 403 didn't have the "windows" above the mains & the last two years did. the olds 403 was also used in trans am's with good results. go for it, their great torque monsters.
 

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Every 403 Olds I`ve rode in had good top end and wasn`t much in the torque field, these engines have a bigger bore than a 400 small block at 4.351 and a stroke shorter than a 350 at 3.385. there power rating in stock form was 180 horses and 320 ft pounds of torque which is respectable, but rates about the same as a stock small block. I`ve read articles on the 403, and the solid webbing blocks are scarce, some sources say they don`t exist. But the biggest thing posted on them was if you want to hot rod it, you`d best be rich.
 

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Too many hobbies!
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I'd have to disagree, too, Double.
We had a 403 in a race car, and i was awesome. Bone stack junkyard engine. Had a helluva time keepin head gaskets in it, but when it wasn't sharing, WOW!

BTW, the head gaskets were user error. Too much time in the mud. It was an enduro, so we had to start on a muddy track. Damn flex fan does move much air, when its wound flat.
 

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eat a beaver, save a tree
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the 78 model block (the first year i think) is the one that doesn't have the windows in the mains. they do exist, i've seen a few but not many. the 403 i had made bunches of torque, but i really don't see how with the short stroke of 3.385". mine didn't make much upper end power, but the torque was great. i wonder if a 455 crank would fit in a 403 block? 505 cubic inch stroker olds. that would have the torque of a peterbuilt lol
 

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bore and stroke aren't the only thing that dictate the characteristics of a motor. If you look at olds motors, you'll notice the intake manifold is decidedly larger than that of a chevy. The long runners influence velocity and turbulence. Remember that when a motor is breathing, its really just moving columns of air and fuel.

K
 

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Back to the main topic of this post, the holes should be in the frame crossmember to simply bolt the Olds motor mounts directly to the frame.

The later 70's GM trucks came from the factory for a brief period with Olds 455's as there was an engine shortage from either an engine plant fire or strike, I can't remember exactly which or which plant either, and from 78-81 with the Olds 350 diesel as an option.
 

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Olds Rocketing along in a Chevy (Good swap)

According to my books, the 403 is 4.351 bore and 3.385 stroke.
the 79 version with 4 bbl was rated at 175 HP @ 3600 RPM and 310 Lb Ft torque @ 2000 RPM. Sounds pretty good to me.
A Chevy 350 in 79 with 4 bbl was rated at 170 HP @ 3800 RPM and 270 Lb Ft torque @ 2400 RPM. While the HP is nearly the same, the Olds definately has the torque advantage.
I dont know about in your area, but 400 Chevies are scarce as hens teeth around here. You cant find one.

Killerformula, I totally agree with you. An engine is nothing more than a piston pump.
 

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Discussion Starter · #16 ·
403 history

A little history is in order to get past the why. My 72 Suburban is my buddy a hard working dog, pulling trailers, boats out of the water ect, I prefer it to my 95 Sub. diesel. The rear end broke a tooth, my intentions were to buy new stuff. I was cruising through the paper and saw this 79 Olds Wagon for sale, the 323 posi-traction was of interest. I want the rear end, I gave the 500 bucks for the car, the motor had 40,000 on a rebuild. I planned on selling the motor and rebuilding a 400 my son has from another Suburban. The 350 in my Sub is blowing a little oil, see where this is headed? After reading on this forum and talking to guys I'm thinking of using this 403. Call Comp Cams have a cam spec'd out along with the gears, valves, springs, pushrods all the stuff, replace the heads with 69 or 70 year model heads built to what the cam needs, Edelbrock intake manifold cleaned up and a 650 or 750 carb what ever is spec'd with the cam. I though just by eliminating the catalytic converter, adding headers and dual exhaust the performance would have to increase.
My problem is I don't know how to spec a cam, I would like to know more about the (cam) relationship between lift and time, spring tension, timing, valve operation, air flow. That's why I will go with an outfit to supply everthing I need for maximum efficiency. Thanks for the reply's and any suggestions are welcome.
 
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