1981 matching numbers or go big hp? - CorvetteForum - Chevrolet Corvette Forum Discussion

Notices
C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette

1981 matching numbers or go big hp?

Old 11-07-2018, 11:50 PM
  #1  
arktraveler
Junior Member
Thread Starter
 
Member Since: Nov 2018
Location: Sherwood, AR
Posts: 3
Thanks: 0
Thanked 0 Times in 0 Posts
Default 1981 matching numbers or go big hp?

I have a very nice 1981 vette. I have worked the exterior followed by the interior. All stock.... except for a moment of weakness when I traded the old stereo for a kick A$$ unit with kicker in back.
Now.... the dilemma of saucing up the pathetic 190hp engine. Of course I can always add $2000 and have the engine pumping out 350hp or more. However, while the th350 is a very strong transmission and can be rebuilt for so little it is still only a 3 speed with a low third gear. This makes that trip on the interstate a very loud affair, thankfully that stereo can drown it out!
An r200 or 700 has a nice OD gear around .70 and they almost fit right into place. So what do you guys and gals say?
Go big or stick with the numbers?

arktraveler is offline  
Old 11-08-2018, 12:43 AM
  #2  
cagotzmann
CF Senior Member
 
cagotzmann's Avatar
 
Member Since: Jun 2011
Location: Sherwood Park Alberta
Posts: 2,083
Thanked 182 Times in 142 Posts
Default

Originally Posted by arktraveler View Post
I have a very nice 1981 vette. I have worked the exterior followed by the interior. All stock.... except for a moment of weakness when I traded the old stereo for a kick A$$ unit with kicker in back.
Now.... the dilemma of saucing up the pathetic 190hp engine. Of course I can always add $2000 and have the engine pumping out 350hp or more. However, while the th350 is a very strong transmission and can be rebuilt for so little it is still only a 3 speed with a low third gear. This makes that trip on the interstate a very loud affair, thankfully that stereo can drown it out!
An r200 or 700 has a nice OD gear around .70 and they almost fit right into place. So what do you guys and gals say?
Go big or stick with the numbers?

Are you thinking the corvette is an investment ? I hope not, so upgrade to suit yourself. Pull the factory motor / tranny and install another crate motor / transmission and enjoy the car.

My base 78 is now enjoyed as a track day car ZZ383 with a T56 Magnum 6-speed. The car still looks factory but now is much much more enjoyable.
cagotzmann is offline  
Old 11-08-2018, 01:32 AM
  #3  
suprspooky
CF Senior Member
 
Member Since: Jul 2016
Location: Blaine MN
Posts: 406
Thanked 27 Times in 26 Posts
Default

Go Big!!!!!!, you can always switch it back. I have a 68 NOM vert that is now 460ci/480rwhp and I wouldn't hesitate to do it again (I'd buy a complete engine tho vs.putting it together like I did).
suprspooky is offline  
Old 11-08-2018, 02:10 AM
  #4  
arktraveler
Junior Member
Thread Starter
 
Member Since: Nov 2018
Location: Sherwood, AR
Posts: 3
Thanks: 0
Thanked 0 Times in 0 Posts
Default

There you go that’s what I was thinking!
How do you like the zz383 and t56 combo?
arktraveler is offline  
Old 11-08-2018, 02:12 AM
  #5  
arktraveler
Junior Member
Thread Starter
 
Member Since: Nov 2018
Location: Sherwood, AR
Posts: 3
Thanks: 0
Thanked 0 Times in 0 Posts
Default

What would recommend as the complete engine for this space? That front end looks 20’ long but most of it is nose.
arktraveler is offline  
Old 11-08-2018, 03:26 AM
  #6  
The13Bats
CF Senior Member
 
The13Bats's Avatar
 
Member Since: Mar 2003
Location: Eustis ( Area 51 Bat Cave ) Fl
Posts: 11,439
Thanked 698 Times in 601 Posts
Default

I like 81s owned two first was my 80s dd,
It served well with its anemic engine and around 88 with 100k miles on it i started to rebuild it ground up,
I was doing well in the music, club biz and hired it finished it got pretty wild, fire breathing 350 and wide body kit.




No, i wouldnt go this far today but ahem, i am flaring out my 69...i have to make the perfect for me c3 because gm didnt.

The 80 to 82 aside from the CE are simply not investment cars, even the ce has to be super nice for anyone to care,
A super lows mile high optioned 80 to 82 all pristine stock with all the ncrs and bloomington awards still isnt all that bucks up and if one drives it at all the worth trickles away,

The only way i would own an 80 to 82 today would be in convertible form ( after factory mod ) and for me a mild bb but if sb is what a guy likes that fine,
Less than about 300hp in a vette is just sad,

Now thats just me opinions vary you have to go with what you want, no one right blanket answer and lifes too darn short to settle.
The13Bats is online now  
Old 11-08-2018, 05:15 AM
  #7  
DorianC3
CF Senior Member
 
DorianC3's Avatar
 
Member Since: Nov 2017
Posts: 413
Thanked 9 Times in 9 Posts
Default

One of the best mods I have ever done was a 200-4R. It transformed the driving experience in a way that more power can't replicate but enhance.
DorianC3 is offline  
Old 11-08-2018, 07:31 AM
  #8  
Bikespace
CF Senior Member
 
Bikespace's Avatar
 
Member Since: Mar 2017
Location: Vienna VA
Posts: 979
Thanked 153 Times in 140 Posts
Default

If you care about numbers matching and sale price, sell it right now. You'll never get it back.

If you go big, ZZ383 and T56 trans for example, even if you do the work yourself, you could be spending $10K or more to do it "right", with all the while you were in there improvements. No offense to you or C3s from the 80s, but that is probably more than you paid for the car, and more than it will ever be worth.

I'd suggest doing it in stages. Make improvements that make the car quicker, if not faster. Suspension mods will help a lot no matter what else you do. The BEST mod for your car would be a manual transmission. If you really want a T56, maybe do that with an engine swap (LS or crate), but a TKO-600 5-speed (close ratio 5th) would be a tremendous improvement and won't break the bank.
Bikespace is offline  
Old 11-08-2018, 07:34 AM
  #9  
Easy Mike
CF Senior Member
Support Corvetteforum!
 
Easy Mike's Avatar
 
Member Since: Jun 2000
Location: Southbound
Posts: 36,266
Thanks: 0
Thanked 821 Times in 756 Posts
Cruise-In II Veteran
Default

Originally Posted by arktraveler View Post
...Go big or stick with the numbers?...
Whatever floats your boat. It's your car.
Easy Mike is offline  
Old 11-08-2018, 08:23 AM
  #10  
jb78L-82
CF Senior Member
 
jb78L-82's Avatar
 
Member Since: Oct 2007
Location: Rhode Island
Posts: 5,939
Thanked 378 Times in 340 Posts
Default

A couple of general comments:

1. C3's are not investments, generally, especially the later years

2. Do not make decisions based on investment potential or lack there of....as others said, do what you want, it's your car.

3. Definitively consider an OD of some sort, Automatic or Manual. I personally would never have an auto, manuals are simply so much more fun and functional...your choice. A stick will transform the driving experience.

4. For the engine, I would consider either a crate 383 or building your current 350 into a 355 Which is what I did with my OEM numbers matching 78 L-82 4 speed gymkhana suspended C3), if you want to retain some semblance of originality, for your own sake. The crate 383 is easier, cheaper, and quicker to complete with minimal effort. I think that I would go crate 383 and the money saved versus building your current 350 into a 450 Gross HP motor you can put into an OD tranny.

The second option of building your current 350 into a fire breathing very streetable 355 with 425-450+ Gross HP will be more time consuming, have better quality reliable parts, will be more satisfying, and more expensive BUT the results will be more satisfying if you have that inclination, retains some OEM quality to the engine, and for the street could have more power easily than most crate 383's. I would not consider a BB engine unless you really feel you must since they are VERY heavy versus the SBC and effect handling, are expensive, and generally you can get 95% of the power of the BB motor in a SBC 383+ today, easily, if built correctly........

Last edited by jb78L-82; 11-08-2018 at 08:27 AM.
jb78L-82 is online now  
Old 11-08-2018, 02:46 PM
  #11  
suprspooky
CF Senior Member
 
Member Since: Jul 2016
Location: Blaine MN
Posts: 406
Thanked 27 Times in 26 Posts
Default

Check out vortecpro454.com I would have gone this route had I known. (500hp minimum for me to use the word big and HP in the same sentence, although by todays standards it's puny)
suprspooky is offline  
Old 11-08-2018, 05:00 PM
  #12  
jb78L-82
CF Senior Member
 
jb78L-82's Avatar
 
Member Since: Oct 2007
Location: Rhode Island
Posts: 5,939
Thanked 378 Times in 340 Posts
Default

Really don't need the bulk and weight of a BB in today's world. SBC is the way to go to make big HP with less weight and less bulk:


https://www.ebay.com/itm/CHEVY-Turn-...-/222893601637

Last edited by jb78L-82; 11-08-2018 at 05:00 PM.
jb78L-82 is online now  
Old 11-08-2018, 05:07 PM
  #13  
fishslayer143
CF Senior Member
 
Member Since: Aug 2009
Location: new iberia la
Posts: 1,209
Thanked 124 Times in 115 Posts
Default

Originally Posted by arktraveler View Post
I have a very nice 1981 vette. I have worked the exterior followed by the interior. All stock.... except for a moment of weakness when I traded the old stereo for a kick A$$ unit with kicker in back.
Now.... the dilemma of saucing up the pathetic 190hp engine. Of course I can always add $2000 and have the engine pumping out 350hp or more. However, while the th350 is a very strong transmission and can be rebuilt for so little it is still only a 3 speed with a low third gear. This makes that trip on the interstate a very loud affair, thankfully that stereo can drown it out!
An r200 or 700 has a nice OD gear around .70 and they almost fit right into place. So what do you guys and gals say?
Go big or stick with the numbers?

my advice?..I bought an 81 in 08.. first thing I did was rip it all apart.. dumped the smog motor, TH350 and tiny 2.87 gears ...THEN I transplanted my 383 CI /525HP with a built up 700r4 and a 3.31 gear .. HUGE improvement but not quite perfect.. yanked the 3.31 gears and put a set of 3.73s in it.. Headers, full dual 2 1/2s with SS Ultra-Flos . WOW! The goldilocks package ! fantastic performance and will cruise smoothly down the Interstate doing 80 mph and only turning 2550rpm.. and gets 19mpg...and sounds great! then I started on the body and paint... and yes I have more in it than I could sell it for, BUT I DONT CARE! ITS A HOOT TO DRIVE and gets stares everywhere when they see it or hear it .. that's my advice
fishslayer143 is offline  
Old 11-08-2018, 05:17 PM
  #14  
cuisinartvette
CF Senior Member
 
Member Since: Oct 2004
Location: Valencia Ca.
Posts: 66,636
Thanked 982 Times in 907 Posts
St. Jude Donor '05
Default

Originally Posted by jb78L-82 View Post
Really don't need the bulk and weight of a BB in today's world. SBC is the way to go to make big HP with less weight and less bulk:


https://www.ebay.com/itm/CHEVY-Turn-...-/222893601637
Good power for 6=7k but to have a 540 for another 1000 is tempting.
I dont get those packages. ..some pieces are decent some are questionable...guess theres a warranty-
Pkus vortecpros will outlast all of em

Last edited by cuisinartvette; 11-09-2018 at 07:43 AM.
cuisinartvette is offline  
Old 11-08-2018, 08:47 PM
  #15  
cagotzmann
CF Senior Member
 
cagotzmann's Avatar
 
Member Since: Jun 2011
Location: Sherwood Park Alberta
Posts: 2,083
Thanked 182 Times in 142 Posts
Default

Originally Posted by arktraveler View Post
There you go thatís what I was thinking!
How do you like the zz383 and t56 combo?
T56 Magnum is a great transmission with any engine combo. As for the ZZ383 I find its a little under powered after 2-3 years of driving, but I think that's normal we always want more power. The best part of the ZZ383 it is a simple setup, I added a serpentine setup, Computer controlled timing with AFR Data logger for tuning the Carb. I think when this engine is done I might choose a LSX block next time and possible EFI vs Carb. But so far these changes has made my 78 very enjoyable as a track day car.
cagotzmann is offline  
Old 11-09-2018, 01:29 AM
  #16  
OldCarBum
CF Senior Member
 
Member Since: Mar 2016
Location: Napa California
Posts: 1,790
Thanked 289 Times in 246 Posts
Default

I'm stroking the big block in my 73 to 496 cu in and swapping my TH400 for a TKO-600RR.
Keep in mind that if you decide to go real big power, you will have to upgrade everything from the water pump to the half shafts.
Building it right costs big money.
Save your pennies, do it right and avoid the money savings create motors with inferior parts.
Have fun and build the hot rod you've always wanted.

Last edited by OldCarBum; 11-09-2018 at 01:12 PM.
OldCarBum is offline  
Old 11-09-2018, 08:22 AM
  #17  
The13Bats
CF Senior Member
 
The13Bats's Avatar
 
Member Since: Mar 2003
Location: Eustis ( Area 51 Bat Cave ) Fl
Posts: 11,439
Thanked 698 Times in 601 Posts
Default

I agree with basically every negative comment about big blocks,
And nope, its not the easiest route,
However,
The positive stigma a bb has for me and has for 4 decades is worth every con, every hurdle others have with them.



The13Bats is online now  
Old 11-09-2018, 01:16 PM
  #18  
OldCarBum
CF Senior Member
 
Member Since: Mar 2016
Location: Napa California
Posts: 1,790
Thanked 289 Times in 246 Posts
Default

Originally Posted by The13Bats View Post
I agree with basically every negative comment about big blocks,
And nope, its not the easiest route,
However,
The positive stigma a bb has for me and has for 4 decades is worth every con, every hurdle others have with them.
I built a 408 cu in sbf and put it into my Factory Five.
Only draw back and negative comment I have is that it wasn't a big block!​​​​​​​
OldCarBum is offline  
Old 11-09-2018, 01:21 PM
  #19  
cuisinartvette
CF Senior Member
 
Member Since: Oct 2004
Location: Valencia Ca.
Posts: 66,636
Thanked 982 Times in 907 Posts
St. Jude Donor '05
Default

Theres a certain visual appeal of a big block, cant deny that plus that thundering deep note.
SBC can make much more power/tq than they could yrs ago but cubes are cubes!
Miss my BB cars they were too much fun..Part throttle, didnt need a lot of gear
cuisinartvette is offline  
Old 11-11-2018, 11:23 AM
  #20  
The13Bats
CF Senior Member
 
The13Bats's Avatar
 
Member Since: Mar 2003
Location: Eustis ( Area 51 Bat Cave ) Fl
Posts: 11,439
Thanked 698 Times in 601 Posts
Default

Originally Posted by OldCarBum View Post
I built a 408 cu in sbf and put it into my Factory Five.
Only draw back and negative comment I have is that it wasn't a big block!​​​​​​​
Yeah i know the feeling because i get it too,
When i used to hit a big show with my modded 66 every sat,
9 out of 10 times the questions would be "whats it got in it?"
Or cut to the chase "big block?"
And my crest would always drop because they could never hide how they really felt when i would say, 327,
I felt the same, i am old school my car is at 50 yo its old school, big blocks are to me the epiphany of what i love about old school cars,
if i wanted modern power i would buy a c7.
The13Bats is online now  

Thread Tools
Search this Thread
Sponsored Ads
Vendor Directory

Contact Us About Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2018 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: