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Gone fishin'
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Discussion Starter #1
I am currently running an Edelbrock Torker intake manifold, and I am thinking about changing it to a better intake manifold. This is where I need yall's help. I am looking at getting a Edelbrock performer RPM air gap intake, what kind of changes would I see if I switched it out such as horsepower and gas mileage since this is a daily driver.

Here is the stats on the engine
350ci
10.3:1 compression
ported heads
camshaft with .314 duration and .510 lift
Edelbrock 750cfm carburator
headers

The engine is in a 86' chevy truck, I Know the carburator is a little big for a 350 but Im using it because it was a good deal on it, and its worked good so far. This truck is my daily driver and It will be seeing the track every once and a while. Thanks for your help
 

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Gone fishin'
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Discussion Starter #3
I have the stock 2.73 gears, I would like to change them out someday for some better ones. Thanks for your help
 

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Those gears are your downfall, performance wise. I bet you would gat the same mileage with about a 3.23 and better performance.
 

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Gone fishin'
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Discussion Starter #5
Thanks for your help, would you know about how much gears like that would cost for me. I don't know a whole lot about the rearend kind of stuff. would those gears fit in the stock rearend housing or would I have to swap that out?
 

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You can get various ratios to fit in your housing, but not sure of costs. Probably cheaper in the long run to find a rear with the ratio that you want at a wreckers or swapmeet and swap the whole thing, rather than pay someone to swap and set up the gears.
 

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poncho62 said:
The Performer should give you better bottom end.

What gears are you running?
The Performer has less mid to top end than the Air Gap. The Air Gap has the same bottom end as the Performer. I don't know why people buy Performers.
 

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gears to go

318 degrees duration sounds like a pretty heavy cam. What is the duration at .050" lift? What brand cam is it?
 

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Discussion Starter #9
The brand of the camshaft is Clevite and the duration at .50" is 254. Its a pretty strong cam, its actually maybe a little stronger than I was planning on getting originally but when I started to build the engine, things got a little out of hand but it turned out pretty good.
 

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which intake

Thats a very lumpy camshaft. I think I would opt for a smaller one, say down around 220- 230degrees, maximum, if I were you.
With that cam you are going to need a lot deeper gear than you have now, say about 3.73 -3.90 for street use. I think you are going to need a little bit more stall in your coverter as well.
Something in the neighborhood of a 2500 rpm stall.
In my opinion, the best way out is to go with a smaller camshaft, especially if this is a daily driver. The cam you are showing is really hurting for bottom end torque, which is what you need for stop and go driving, daily.
 

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Discussion Starter #11
Well I already have put in a torque converter with a high stall so thats already taken care of, but I have been planning on getting new gears, is there any rearend that I could look for at a swap meet or junk yard that would have gears like that.

Thanks for all your help
 

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rear end

You have to go a long way to beat a 9 inch Ford. Just watch for the splines. They were made with both 28 and 31 spline axles.
If you can get a 31 spline all the better. The 28 will hold your engine but if you have the option, go for the 31.
The track width on your pickup and on most Ford pickups is about the same. If anything, about all you will have to do is relocate the spring mounts. The ony other thing is that you will have to run Ford rims on the rear, unless you want to go to the hassle of redrilling your rear hubs to take the Chevy pattern. Ford truck rear ends us a 5 1/2 on 5 bolt pattern. Passenger cars use a 4 1/5 on 5 pattern.
Your Chevy is either 4 3/4 on 5 or 5 on 5. Having the axle hubs redrilled for your Chevy pattern is probably the best way to go in the long run as it saves you from having to carry two spare tires, and the cost of the extra tire and rim should about cover the cost of having your hubs redrilled.

Another nice thing about the 9 inch is that gears are a dime a dozen. You could actually set up two pumpkins. One for street and one for racing. It only takes about an hour at most to swap pumpkins out. You cant do that with the Dana type rear you currently have. Most of the 9 inch I have come across in pickups have between 3.25 and 3.5 gears, the latter being a fair compromise gear for your engine for street, and if you are going to drag race it, a 4.11- 4.25 would probably fit the bill. Be warned, finding a rear end with a Detroit Locker or Equa-Lock diferential could be a rare item. That would be the setup for the drag gears.
On your carburetor, unless you have a double pumper or have put a light spring in the secondaries, you probably arent getting that 750 fully opened up anyway.
 

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Discussion Starter #13 (Edited)
ok Thanks for all your help, Its greatly appreciated.

I also have one more question, about how much would a rear end like that cost me at a swap meet, Im asking this because there is one coming up here in Wichita Falls next week and I was gonna try to find one.
Thanks again
 

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rear end

A 9 inch in real good condition could easily run you $300, but then its all a matter of how much you want to haggle. Remember one thing.
Were it me, I would rather take my chances on something like that at a salvage yard. That way, if something is wrong with it, you can take it back. Not always possible with stuff gotten at a swap meet.

As for the splines in on the axles. A rule of thumb is if it had a 6 or a 302 in front of it, most likely its a 28 spline. The larger engines usually all have the 31 spline. If it had a 351 in it (W or M), it could be either one.

Best bet is to get one out of a pickup that had a big block.
 
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