Big Block conversion question
Thread Starter
Safety Car
Joined: Jul 2001
Posts: 3,921
Likes: 2
From: York PA
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:
Burning Brakes
Joined: Apr 2001
Posts: 752
Likes: 1
From: Springfield Oregon
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]
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]
Le Mans Master
Joined: Oct 2000
Posts: 6,563
Likes: 2
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]
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]
:yesnod: :chevy :chevy :yesnod:
Big Blocks rule.
Racer
Joined: Sep 2001
Posts: 267
Likes: 0
From: Midland TX
Re: Big Block conversion question (ORVette)
Short Corvette specific water pump, ....
[Modified by ORVette, 5:05 PM 2/15/2003]
[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:
Burning Brakes
Joined: Aug 2001
Posts: 1,002
Likes: 0
From: Bay City MI.
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.
Melting Slicks
Joined: Sep 2001
Posts: 2,068
Likes: 1
From: Gig Harbor WA
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.
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.
Safety Car
Joined: Aug 2000
Posts: 3,909
Likes: 26
From: Clymer PA
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.
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.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
2027 Corvette vs The World: Every Model vs Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
10 Things C8 Corvette Owners Hate (But Won't Tell You)
Joe Kucinski
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!
Brett Foote
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)
Joe Kucinski
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!
Michael S. Palmer