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I'm looking at a 73 L48 4 speed, I am considering it since the birdcage, frame, and body are excellent. It's matching numbers and seems sound mechanically.
Without tearing engine apart does a distributor recurve and carb jetting make it a decent performer? Would that make it similar to say a 1970 350 300 H P gross rating SOTP feel.
Or for a 1973 Vette should I just be looking for a L82.
I'm not drag racing just don't want a cool looking Vette that's a slug.
I currently also have a 1964 Impala SS 4 speed 327 300 with a cam upgrade, that car is what I call a decent runner. I know a 73 L48 Vette is lightyears from a 70 LT1 I had years ago.
Not certain if you have taken this car for a test drive. But would recommend you do. after nearly 50 years no telling what's been done tuning wise.
In answer to your question. yes properly set up this car would be close. not there, but close to that 300H.P. you mentioned. gearing makes a huge difference. Lots of variables.
And a slightly hotter cam, better heads, .... well you did say you didn't want to take apart the engine.
The L82 has better bones to be certain in the engine department. But the L48 really doesn't take much to get it to 300 crank HP.
Remember gearing makes a big difference.
Not certain if you have taken this car for a test drive. But would recommend you do. after nearly 50 years no telling what's been done tuning wise.
In answer to your question. yes properly set up this car would be close. not there, but close to that 300H.P. you mentioned. gearing makes a huge difference. Lots of variables.
And a slightly hotter cam, better heads, .... well you did say you didn't want to take apart the engine.
The L82 has better bones to be certain in the engine department. But the L48 really doesn't take much to get it to 300 crank HP.
Remember gearing makes a big difference.
and in that regard, didnt L82s come with 3.55 gears and l48s 3.08 standard? I may be wrong but I thought I recently read this in another thread.
OP you will not be able to tell the difference in power driving around town and if you do notice a difference at city speeds from light to light the chances are you would think the L48 was snappier. Car and driver reported this in the original tests. This is because the smaller l48 cam has slightly better torque if anything when taking off at a light (which is another reason I thought the l82 had 3.55 gears to help compensate.) The L82 has more hp and a higher rpm range and a forged internals so if your going to hot rod it up some and rev it above 6,000 rpm its a better choice.
Last edited by augiedoggy; Aug 9, 2021 at 07:40 AM.
Not certain if you have taken this car for a test drive. But would recommend you do. after nearly 50 years no telling what's been done tuning wise.
In answer to your question. yes properly set up this car would be close. not there, but close to that 300H.P. you mentioned. gearing makes a huge difference. Lots of variables.
And a slightly hotter cam, better heads, .... well you did say you didn't want to take apart the engine.
The L82 has better bones to be certain in the engine department. But the L48 really doesn't take much to get it to 300 crank HP.
Remember gearing makes a big difference.
Thanks for your comments. Did not test drive and don't know it's history but it idles as smooth and quiet as a church mouse. I'm just on the fence in buying a 190 H P Vette. I'm tempted as how easy will I find again one with near perfect birdcage, frame, and body.
So, is a L82 a real Vette, still a muscle car, and a L48 the "Oh, you bought a L48, that's nice".
Thanks for your comments. Did not test drive and don't know it's history but it idles as smooth and quiet as a church mouse. I'm just on the fence in buying a 190 H P Vette. I'm tempted as how easy will I find again one with near perfect birdcage, frame, and body.
So, is a L82 a real Vette, still a muscle car, and a L48 the "Oh, you bought a L48, that's nice".
190hp? my 74 l48 was 205hp from gm... before I swapped the engine. I would think the 73 would be higher than 190. I dont believe the ratings got that low until the late 70s.
EDIT your right... the L48 was rated at 190 and the L82 either 210 or 250 depending on which specs google gives you...... its due to flat top pistons vs dished and bigger camshaft.
strangely my 74 l48 was rated at 195hp.. I have my original l48 on an engine stand in the garage and something I can have more fun with in the car. Keep in mind you could bolt on 64cc or even 58cc heads and make more power with the l48 than the stock l82..
Last edited by augiedoggy; Aug 9, 2021 at 08:00 AM.
hp ratings may be in gross or net or both
chevy 72 & up all net
71 BOTH gross & net
70 & back all gross
e.g. compare & contrast apples to apples 71 vette L48
HP -- Gross 270 @ 4800 versus Net 210 @ 4400
TQ -- Gross 360 @ 3200 versus Net 300 @ 2800
largest two physical changes occurred 71 & up when all GM models suffered large drop in compression ratio
then 75 & up when all suffered restricted exhaust flow via catalytic convertors and few "true" dual exhaust.
JMO, nearly all of the HP-TQ differences between 71 thru 74 L48 are due only to tuning ... all same bore stroke piston cam essentially same heads ... again 71-74 L48. YMMV.
It’s relatively easy to squeeze some extra HPs out of that engine. Tons of threads on here explaining how. Finding an unmolested and rust free 4-speed car makes it a worthwhile purchase. My 73 was born with a TH400 and 3.08s. I wish I’d held out for a 4-speed. But dropping in a 460hp 383 has helped dry my tears. 73s are finally increasing in value after being overlooked for so long. Last year of the chrome bumper.
I'd purchase and if you want something more fun. Pull the origianl out and put something more fun in. Looks great. If you choose not to get send me the information please.
That is a pretty 73, I don't care for the steering wheel but that's nothing AND my opinion means nothing. You have to decide on what you want- don't buy it to impress other people as there will always be a nicer, faster, vette out there. Buy it because you want it. An L48 4 speed isn't going to beat anything at the drag strip but it will be a nice car to drive and cruise in and as long as that is what you want go for it.
If the car looks as good up close as it does in the pictures I don't think that's a wildly unreasonable price. Maybe a tad high. If it were a big block or convertible it could bring over $20k but I think it's closer to the $16k - $18k range. Did he volunteer the fact that he would take less than the list price or did you get him to come down? If he offered to come down right off the bat, that means no one is biting at that price. Offer $17k and give it a week or two. Obviously this is just my take on it, how I would approach it. If you love the car and don't want to dicker over a few thousand dollars, pull the trigger! You'll take home a beautiful machine that will put a smile on your face and get looks everywhere you go.
fwiw, tried & true upgrade for 71 & up L48 is raise compression and enlarge cam. Today's TFS'-lifters DHC 175 heads w/ 60cc chambers are a good mate to L48 dished pistons. Heads & a swap to somewhat larger cam-lifters & that'll really wake it up! May improve mileage as well.
If the car looks as good up close as it does in the pictures I don't think that's a wildly unreasonable price. Maybe a tad high. If it were a big block or convertible it could bring over $20k but I think it's closer to the $16k - $18k range. Did he volunteer the fact that he would take less than the list price or did you get him to come down? If he offered to come down right off the bat, that means no one is biting at that price. Offer $17k and give it a week or two. Obviously this is just my take on it, how I would approach it. If you love the car and don't want to dicker over a few thousand dollars, pull the trigger! You'll take home a beautiful machine that will put a smile on your face and get looks everywhere you go.
AND.....don't get wrapped up in horsepower! There are may simple things YOU can do to that car to impress YOURSELF from one traffic light to the next. Keep in mind you are saving at least $10,000 on a good paint job since the car already looks great.
YOU can change the diff. gears yourself or have a shop do it by going from 3:08 to 3:43 and it wont put a dent in your piggy bank...same thing with ceramic headers--just to mention a couple changes that could happen without having the car on jack stands for a month (or year).
Even if he comes down only $1,000, you are saving enough to get more H.P. out of the drivetrain.
I'd say offer him $2,000 less than he is asking so he doesnt toss your phone number in the waste basket.....and tell him you'd like to close the deal when he gets back to you.
and split the difference if the car is as good as it looks.
(For example: I will have nearly $20,000 in my basket case project having done all the work myself. And I will be doing handstands once I complete it. MEANWHILE...you can buy that car ready for F U N !)
WE can all make a "Better Deal"....Just don't lose a chance at a Great Deal!
Last edited by doorgunner; Aug 9, 2021 at 03:15 PM.
Chevy was pretty careful despite all the emission laws coming in NOT to have a 'sluggy Corvette'.
If you go back thru all the Car and Driver/R&T/SCG/ articles...
SBCs were between 6.5 and 7.5 sec 0-60....NONE WERE SLUGS.
Right now I'm looking to add a '79 to my stable.... L-48's are FINE. In 79 for instance....the standard rear axle was 3.55 you couldn't even order a 3.08....because Chevy thought that was too 'sluggy'.
Remember the old SAW ; You SPEED horsepower...you DRIVE Torque..
I would concentrate on the Torque numbers....you use that every day.
A L48 camshaft is good for 300 crank hp. period. As can see from the factory graph for a ZQ3 (a high compression L48 rated at 300 crank) the .390/.410" cam runs out of steam around 4500-4800 rpm
The only thing of substance you can do with your engine keeping that camshaft is raise the compression ratio through smaller CC heads to make it into a ZQ3. Changing the cam to something bigger would be the only route if you want more. Keep in mind that 300 hp in a 3000 lb corvette is no slouch either. The ZQ3 in my 2900 lb '69 with a stock 336 ratio scoots along just fine for me.
1973 L48 question
