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Big Block conversion question

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Old Feb 15, 2003 | 07:32 PM
  #1  
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From: York PA
Default Big Block conversion question

I am trying to figure out about how much it will cost for me to convert my '81 to a big block. I need to know a little more about the accessories. Will I be able to get brackets to use the accessories off of my '81 (PS, ALT, AC) or will I need to buy different accessories. Thanks :cheers:
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Old Feb 15, 2003 | 08:03 PM
  #2  
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From: Springfield Oregon
Default Re: Big Block conversion question (stickboy)

Probably around $2000, plus the motor. You'll need big block specific brackets, pulleys, PS pressure hose, possible cooling system upgrade, headers, a little exhaust work, possibly a bigger carb than you have now, fuel pump, Low rise LS6 manifold if you want it to fit under your stock hood, might as well throw in some new poly motor mounts, Short Corvette specific water pump, ....
Some of the other BB swap guys will check in with whatever I missed, I'm sure there's a few things. It's not cheap, as I'm finding out. Luckily, I traded another car I had for my motor, so I didn't have to set out cash for that. You will also need to do some suspension upgrading most likely. In addition, I ordered a super brake kit from Muskegon, to make sure this thing will stop if I ever get it done. Good luck!

PS-manifold part only applies if you get rectangle port heads. I think there are more choices for oval ports.


[Modified by ORVette, 5:05 PM 2/15/2003]
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Old Feb 16, 2003 | 06:35 AM
  #3  
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Default Re: Big Block conversion question (ORVette)

Probably around $2000, plus the motor. You'll need big block specific brackets, pulleys, PS pressure hose, possible cooling system upgrade, headers, a little exhaust work, possibly a bigger carb than you have now, fuel pump, Low rise LS6 manifold if you want it to fit under your stock hood, might as well throw in some new poly motor mounts, Short Corvette specific water pump, ....
Some of the other BB swap guys will check in with whatever I missed, I'm sure there's a few things. It's not cheap, as I'm finding out. Luckily, I traded another car I had for my motor, so I didn't have to set out cash for that. You will also need to do some suspension upgrading most likely. In addition, I ordered a super brake kit from Muskegon, to make sure this thing will stop if I ever get it done. Good luck!

PS-manifold part only applies if you get rectangle port heads. I think there are more choices for oval ports.


[Modified by ORVette, 5:05 PM 2/15/2003]
Just about right on..........
:yesnod: :chevy :chevy :yesnod:
Big Blocks rule.
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Old Feb 16, 2003 | 06:29 PM
  #4  
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From: Midland TX
Default Re: Big Block conversion question (ORVette)

Short Corvette specific water pump, ....
[Modified by ORVette, 5:05 PM 2/15/2003]

I am in the process of converting my '72 into a 454 and now I have a question. I thought the big block used a long water pump not a short. Am I wrong? :confused:
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Old Feb 16, 2003 | 06:39 PM
  #5  
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From: Bay City MI.
Default Re: Big Block conversion question (Obdoc)

You will for sure need the short pump if you keep the original fan setup, if you go with electric fans then you can use the longer pump. That is the setup I have, which happend by accident.
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Old Feb 17, 2003 | 08:13 AM
  #6  
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DREGSZ
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From: Gig Harbor WA
Default Re: Big Block conversion question (467-Ratman)

You will need a 168 tooth big block specific flywhell/flexplate.
I will have a flex plate to sell next week as I am getting a flywheel for my 4 speed.

What are the intake manifold options for oval port heads?
I was going with an Edelbrock Torker since I have a stock '74 hood.

You can get the brackets from Volunter.
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Old Feb 17, 2003 | 11:27 AM
  #7  
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From: Clymer PA
Default Re: Big Block conversion question (Evan Ginsberg)

The big block to small block conversion cost me about $4500 or so for the motor (built it myself) and about another $1500-$2000 for other things that I needed, such as brackets, aluminum radiator, blowproof bellhousing, clutch etc...

If you want to stick with the stock hood your intake choices are very limited...especially if you have R-Port heads. A Torker II will fit under the hood but it's a O-Port intake. I tried the Torker II, I slightly ported it and gasket matched it. It really held back my motor to the tune of 5mph down the 1/4 mile and .5 of a second. I have since switched hoods and intakes. I am now running an L88 hood with a Strip Dominator intake.
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Old Feb 17, 2003 | 03:56 PM
  #8  
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From: High Point, NC
Default Re: Big Block conversion question (Obdoc)

depends on the year mine used the short pump :steering:
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Old Feb 17, 2003 | 03:59 PM
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Default Re: Big Block conversion question (stickboy)

Don't forget about suspension. you will need heavyer front springs
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