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-   -   Aluminum inner fenders? (https://67-72chevytrucks.com/vboard/showthread.php?t=574692)

69GMC910 04-08-2013 02:44 PM

Aluminum inner fenders?
 
Anybody here know anyone that custom makes them for
73-87's? I have seen the fibreglass ones but prefer the aluminum...
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INSIDIOUS '86 04-08-2013 04:11 PM

Re: Aluminum inner fenders?
 
For bagged drops or aluminum oem style?
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69GMC910 04-08-2013 04:17 PM

Re: Aluminum inner fenders?
 
Just something to lighten the front end for drag racing.
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INSIDIOUS '86 04-08-2013 04:37 PM

Re: Aluminum inner fenders?
 
Most just take them out. But it may be possible (small slim chance)
That you can make a call to gm goodmark repop and have them press aluminum instead of steal.

I wanted to do this with the front fenders an inners myself along with the bumpers. Kinda like the old z33 rpo that never happened. All the front was aluminum.

Meanwhile a fiberglass hood will net a greater margin of weight loss
Plus moving things back help so a blazer tank instead of saddle tanks and rear mount battery help hooking up.
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69GMC910 04-08-2013 08:52 PM

Re: Aluminum inner fenders?
 
What is the weight of a factory hood? 80 Lbs?

B Barber 04-08-2013 09:36 PM

Re: Aluminum inner fenders?
 
A few questions and we may can come up with a recipe for you.

1. What is the weight of your truck with you in the seat and a half tank of gas?
2. How much HP does your engine make?
3. What tires are you running out back?
4. How fast do you want to go? (I know this one is tricky!, we are never fast enough)

69GMC910 04-08-2013 09:50 PM

Re: Aluminum inner fenders?
 
Roughly 4150, 707hp, 30x12's, low 11's.
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B Barber 04-08-2013 09:52 PM

Re: Aluminum inner fenders?
 
With those numbers you should already be at that time. Have you had your engine dynoed?

you can get deep into the 11's and possibly into the 10's with that HP and weight, but a gear swap may be needed to get you there. Are you having any issues putting the power to the ground, or do you have any traction helpers?

INSIDIOUS '86 04-08-2013 10:05 PM

Re: Aluminum inner fenders?
 
Need much better gears than 3:42
What's your trap speed rpm and mph?
What else have you done to it?
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69GMC910 04-08-2013 10:08 PM

Re: Aluminum inner fenders?
 
Engine was dynod when built, I am nearing completion of the reassembly of the whole drivetrain... Hope to fire it by the end of next week. I have the 3.42's as I plan to use this 80% on the street. I will run 30x10 radial slicks @ the track, and I am running Caltracs on the leafs. Once I get the rear lowered I can measure for my adj. shocks, driveshaft, etc...
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INSIDIOUS '86 04-08-2013 10:15 PM

Re: Aluminum inner fenders?
 
3:42s are going to kill you at the track. When you lower it get the front spring eye as high as you can and get the instant center working for you. I would suggest a built 2004r overdrive trans and 3:91s which will Prob get you to your goal and still be more street freindly than your current setup. But I'm certain you Prob have the th400 built real well.
Tonneu cover helps too.
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69GMC910 04-08-2013 10:20 PM

Re: Aluminum inner fenders?
 
I fail to see how the 3.42's kill me? At 700 ft lbs does the gear really make that big of a difference? It's a TCI Super Street Fighter with an ATI 3200 stall.
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B Barber 04-08-2013 10:25 PM

Re: Aluminum inner fenders?
 
If you are looking for better track times, gears are a major factor. Big blocks need less gear, but I would recommend a 3.90 or similar to give you the best of both worlds
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B Barber 04-08-2013 10:26 PM

Re: Aluminum inner fenders?
 
How much boost was those HP numbers on?
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69GMC910 04-08-2013 10:27 PM

Re: Aluminum inner fenders?
 
zero boost.

B Barber 04-08-2013 10:33 PM

Re: Aluminum inner fenders?
 
I mean no offense whatsoever here, but I don't trust those hp numbers. Not saying they are wrong, but it is very unlikely for a 496 to put those numbers down. Not impossible, just unlikely on pump gas. But that is neither here nor there. Gears will really help you out a lot
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69GMC910 04-08-2013 10:37 PM

Re: Aluminum inner fenders?
 
Proof is in time slips, and my builder's engines are in all of the fastest BB steel headed Chevelles in the USA. If I told you my cam specs you'd doubt it even more!

69GMC910 04-08-2013 10:43 PM

Re: Aluminum inner fenders?
 
We are waaaaay off track here though! I see the glass hoods weigh about 40 lbs for the ones that are not just pinned down... What does the factory hood weigh? I saw on Goodmark that it's 124 lbs? SERIOUSLY??!!! I sent them an email regarding an aluminum re-pop... We'll see if they reply!

B Barber 04-08-2013 10:44 PM

Re: Aluminum inner fenders?
 
Lol. Wasn't saying it was wrong. I know that sounded bad tho. What times have you ran so far?
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69GMC910 04-08-2013 10:58 PM

Re: Aluminum inner fenders?
 
As mentioned just finishing assembly in the next few weeks here. I don't expect to be blasting low 11's right off the bat or anything. I am going to need to re-learn to drive it before I can go hard on it... Going to be quite a difference compared to the 340hp 383 it replaced! And I know you meant no harm! I just hope everything goes together smoothly so I can get the darn thing on the road!

P.s. Your truck is F'n AWESOME. Love the rear meats!

INSIDIOUS '86 04-08-2013 11:05 PM

Re: Aluminum inner fenders?
 
Quote:

Originally Posted by 69GMC910 (Post 5999776)
I fail to see how the 3.42's kill me? At 700 ft lbs does the gear really make that big of a difference? It's a TCI Super Street Fighter with an ATI 3200 stall.
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Gotta look at what your pulling down the track. A barn pretty much. Gears are going to make more difference in the truck vs the car. 3000stall may be a little small as well but for the street it's good enough to keep it drivable slightly

Maybe you should look at gear vendors overdrive and new 3:91 gears

Are you using a truck 12bolt as well?
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69GMC910 04-08-2013 11:13 PM

Re: Aluminum inner fenders?
 
Yes truck 12 bolt. 3.42's, Eliminated c clips, big bearings @ axles, Ferd drums, Mark Williams axles etc.

Here is a 657hp steel headed version of my engine. Mine has aluminum heads, and 50 more hp. I realize this guy is in an arrow and I'm in a brick! His gears were 3.08 at the time of this video. He has since switched to 3.31's and has a best of 10.59.


69GMC910 04-08-2013 11:16 PM

Re: Aluminum inner fenders?
 
2 Attachment(s)
The 12 bolt

INSIDIOUS '86 04-08-2013 11:22 PM

Re: Aluminum inner fenders?
 
Truck 12 bolts have a small pinion shaft diameter. The truck ten bolt actually has a bigger pinion gear and when built will do 10s reliably. So watch that pinion!

Let me know what you head from gm goodmark. If they short you see if you can get a higher up person on the phone
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69GMC910 04-08-2013 11:28 PM

Re: Aluminum inner fenders?
 
Yeah, I asked about it and mentioned possibly a bulk order. Asked about inner and outer fenders. Hopefully it works out!!


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