Replacing subframe for a BBC?

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  #11  
Old 09-21-2012, 07:37 PM
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Originally Posted by reidski182
Really appreciate the in-depth reply. I'll begin research on "subframe connectors" because I'm not entirely sure what that means, as I am just getting into cars and such. And the info about cams is very helpful, I will make sure to get everything else done first, I suppose. I have a lot to think about! Luckily I have a buddy or two that can help me out with the cam, but any suggestions I can bring to him are great.
One of the best things you can do to make a 454 run better is the older oval port heads as found on the early 396-402-427 engines. These are great street strip heads, and with a little larger valve they really bring the later 454 engines to life. I've had great performance from mine, and I did the valve swap, plus went with SS valves and hardened seats.
For a cam I went with 282/282 (advertised duration) with .530/.530" lift, and 112 LSA. This cam is lopey idle, but will work with a stock torque converter, and makes good power from off idle to 5700 rpm. I am running the stock bottom end forged crank, and TRW forged pistons. It's been a dependable engine, and a great street/strip engine. Don't let people talk you into something huge in a cam, unless you plan to spend most of your time at the drag strip.
 
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Old 09-21-2012, 08:15 PM
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Our cars are unibody cars. Meaning they don't have a real frame. The shell is built with the rear frame sections welded in as part of it structure. Then on the assembly line the front subframe assembly was bolted to the shell. Almost everything made today is unibody.

The other way is to build a frame and set the body down on top of it.

The red lines represent where SFC's would go. They basically stiffen the car because the roof, doors and floor aren't up to the task. I believe in adding these at any power level. It just makes the car "feel" better. Plus some of the squeaks and rattles go away.

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Old 09-21-2012, 11:23 PM
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Thanks so much for the info, guys. I needed the extra 454 info because like I said, just getting into it. As for the subframe connector, how tough is the install?
 
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Old 09-21-2012, 11:52 PM
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Not bad. Buy a wbolt in set and weld the rear section in and bolt the front.
 
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Old 09-22-2012, 12:39 AM
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Sounds easy enough, even for a guy like me! I guess it's official then, BBC here I come! Restoring a 454 though, I think that's a whole 'nother story. Glad to know this forum's active and helpful!
 
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Old 09-22-2012, 07:15 AM
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Like Val mentioned though,just watch how crazy you get with the cam,to much and you wont have enough vacum to run things like power brakes etc.
 
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Old 09-22-2012, 02:29 PM
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Hate to beat this dead horse, but just so no mistakes are made, this is what I need, right?

Competition Engineering 3113 Competition Engineering Subframe Connectors
 
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Old 09-22-2012, 05:51 PM
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Originally Posted by reidski182
Hate to beat this dead horse, but just so no mistakes are made, this is what I need, right?

Competition Engineering 3113 Competition Engineering Subframe Connectors
Yes, those are the subframe connectors. Those are boltins front and rear, so no welding needed. I've heard of some guys taking the weld in connectors to their local exhaust shop and having them do the welding, if you choose to go that route.
The only concern with boltin connectors is the bolts. Often these old cars have never had the rear spring bracket bolts, or subframe bolts removed, so there's always the chance they're rusted in and wont come out, or break. Just be prepared to fix what wont come out!
 
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Old 09-22-2012, 06:14 PM
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Originally Posted by 1971BB427
Yes, those are the subframe connectors. Those are boltins front and rear, so no welding needed. I've heard of some guys taking the weld in connectors to their local exhaust shop and having them do the welding, if you choose to go that route.
The only concern with boltin connectors is the bolts. Often these old cars have never had the rear spring bracket bolts, or subframe bolts removed, so there's always the chance they're rusted in and wont come out, or break. Just be prepared to fix what wont come out!
Alright, sweet. I think I'll just replace the bolts if I can, sounds less intimidating than welding
 
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Old 09-22-2012, 07:38 PM
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I own a set of the weld in ones like the ones you posted. Wanna know why they aren't in a car? Be Comp Engineering (yeah right engineering) designed them to only work with their own rear frame replacements. And those require you to narrow the tank. AND the SFC must be run through the floor of the car. AND relocate the front of the spring to bolt into the connector. Easy driveway project right? If you tracked back to my very first poet here, you would find me asking if anyone had ever do this. I have yet to find ANYONE who has done it. I have seen a pic or two that others have found on the net. But no one that can tell me what happened. Honestly I want to use them because they move the spring eye over and I could fit bigger rubber along with the mini tub. That would save hundreds.
 


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