Hello friends,
I would like some opinions please. I have an original 1973 vette with 63,000 miles but it does have the 195 HP SBC. I have been in discussion of having the engine and gaining more horsepower. My restoration person says my options are limited if I want to have under the hood to look exactly the same as it does now. He said maybe 400 HP. However if I am willing to have some change in looks then he can do Vortec heads and maybe a supercharger. I have always wanted to keep the car original to hood it’s value. Do you think 500 or even 600 HP under the hood would detract from the value? Any ideas or suggestions I can bring to him on increasing HP with a rebuild? I wanted to keep the original block.




thanks Michael

 

I am the second owner of a 74. It had the same engine as yours. Like you, I wanted to improve the horsepower so I replaced the cam. I don't recall that change doing much except making it sound faster. (It was a classic 30-30 mechanical lifted cam.) Eventually I built a new engine for the car but with only modest horsepower goals. I wanted to hit 385 HP. In the early 1990's this was pretty respectable. Without going into additional details, I basically increased the compression ration (to 10.1:1), replaced the heads with the best I could find (AFR 190cc aluminum), and replaced the cam.

I'm happy with where the engine is now. I did learn a couple of lessons. One, you need to get the right cam. The first cam I used following the rebuild sounded great but was the car was a real dog. I turned something like 15.5 in the quarter. I replaced the cam with another with great improvement. I haven't actually run the quarter with the current cam but I would project it at high 13's.

If you go the route many will suggest, bigger displacement, etc., be prepared for other things to become money pits. To get traction with anything much bigger you'll need to run drag radials. That will lead to beefing up the rear suspension. Even a moderate upgrade like mine will probably lead to cooling problems and you'll want to replace the radiator.

Your engine compartment looks nice to an originalist like me. I'd find some good flowing heads with a small combustion chamber, leave the block alone and keep your Q-jet carburetor. Paint the heads to match the block, leave the air cleaner as is, forget trying to out street race all the newer 500 hp mustangs and enjoy your classic car. It will definitely retain the original under the hood look.

 

Are you building the car for you or some guy that might buy it someday?
Plenty that like stock and modified dont worry about it. You never get your $ back anyways

If you want power then go build for it. Your block is probably a 2 bolt main you could easily give it a good 450hp without a problem.
If you want that number or higher move on to better heads than the vortel I dont think a supercharger is needed to get that #

If it were me just order up a healthy 400 crate engine then bolt all your accessories back on..
It would look close to the way it does now yet make way more power...and big block torque.
Just know most these crate places rate theri power in a dyno cell with no accessories hooked up, col air etc. So that 450hp engine may only make 400 or less by the time you install it

 

I would do the crate engine also and store your original engine if it's #'s matching. A 450-500 hp 383 crate should fit the bill.

 

IMO you need to take the original engine to some one who specializes blueprinted production engines, you have the engine built to L82 specs with a twist, very light weight internals, 1.5 1.5 3.0 ring pack, the crank counterweights would be cut down and bull nosed, the stroke would be set and indexed. I would take the factory L82 cam and grind it on a original GM cam core and coat it and change the LC to 112 precision ground, new lifters would be from 1970s stock. The factory heads would use a 1 piece bronze guide honed to size, chrome stem stainless steel 2.02/1.60 valves, porting designed to enhance low lift flow, screw in studs and guide plates would be used, CCs would be set along with a 9.3 compression. A custom forged long skirt piston lightened with the wrist pin moved .022 down to set deck height. Factory rods would be center to centered, press would checked, ARP bolts installed, resized. The intake would receive mild port work, the factory Q-Jet would get worked by a pro. Same with the HEI. The original oil pan would be modified internally. NOW: you will not have 400 HP, but you could have a real VERY responsive 350 plus HP that would be a night and day difference from the L48, the drivability would actually be much better than the original engine...........thats how I'd do it.

 

I hear theres a guy in Colorado thats pretty good at doing the above.
Op maybe you should pm Vortecpro and ask him questions

 

I'll say you won't get to 500hp with the stock manifolds and stock heads. Performance intake, heads and headers will no longer be pure stock configuration. So you need to state how much modification you can accept.

FYI Smokey Yunick (RIP) said building a 560hp small block Chevy will cost 5 times as much as a 500hp small block Chevy to build. A 383 stroker with cam, heads and manifolding that all compliment each other can "possibly" make 500hp.

Good luck.

 

How sneaky does it need to be? You can paint heads and intakes........
Mark Vortecpro has good but a bit pricey suggestions......my take is that he has built some Top Stock stuff
The 66' in my Avatar was a 331 with 80 hours in the heads.....a stock L-79 cam on 1.6 rockers, 2.5" Rams Horn manifolds, Factory sides, 2101 Performer intake and a 650 AVS carb......with a 3.36 gear and a wide ratio muncie it ran high 13's on 215 wide rubber........the trick was the low to mid lift flow Vortec mentioned......this engine had ***** midrange, but the factory exhaust made it peter out at 5600.......sounded great, pulled 15-16 mpg at a steady 70 MPH on I-35........ran like a watch. I regret trading it off.......

Jebby

 

Thanks for all the information I appreciate the input. I will show my mechanic. He spends a lot of time discussing all of this with me. I am leaning to what Gearhead74 suggested. My mechanic says he can probably get the rebuild close to 400hp and still look all original. This was his original suggestion. I am concerned that yeah one thing leads to another and I would be opening up a can of worms with having to change so much. The mechanic assured me very little would need to be changed for this effort but he could do Vortec heads or a supercharger and to would be a different look.

Besides, for those mustangs my other car is a Cadillac Vsport
thanks

 

When your mechanic passes you his estimate, ask him how much to install a 383 crate. It will still look as original as reworking your own engine but a lot less cost, time and effort for the same results. But if money is of no concern, have at it.

 

I will ask about the 383 crate. I like acting like I know engine stuff. He did say I am to keep all the original parts no matter what I decide. Thanks

 

You can put a good head on it,paint it to look stock thats where the power is.
You should really put headers on it at least...you can get or fab up the smog tube fittings....wouldnt look out of place lots of cars have them
With all the stock stuff under hood noone would suspect it was fast.
That super stock/blueprinted type build Vortecpro suggested would be fun.
ID be tempted to at least drop a cast 3.75 crank in it, cant see that
What do you have to spend?

 

As far as budget. He had originally told me about $5,000 to rebuild the engine. I figure between 5-8k would be ok. Anything more I think is silly. I would be happy with 400hp, really happy with 500 but would not want more or I would be afraid I would have to upgrade many other things.

 

For 5k you can geta 383 with HR cam nice heads if youre careful. Youll love the way that feels.
At least youre realistic, factoring in "little $tyf", while Im at its, most dont.
They look at the price of an engine and figure they are gonna do a Budget build, rarely happens. lol

 

Keep in mind that you get what you pay for.
Your mechanic is giving you a good quote for a rebuild of your factory engine that will produce 400 +/- hp.
Ask him which parts he plans to use and ask him about upgrades to the parts to insure he uses top quality components.
The better components will cost more, but your budget range is pretty open and it might only add $500.00 to $1,000.00 more to the build.
Your original two bolt block will work perfect for you.
I would stay clear of cheap stroker crate motors.
Some use inferior components and cheap labor to keep their costs down.
The original drive train in a C3 was designed to stand up to about 450 hp.
It becomes extremely expensive to start building the drive train to take the abuse of additional hp and tq.
It’s not “going down the rabbits hole”, but more like falling into a well to upgrade.
Jebby gives excellent advice above and he is one of the most trusted voices here on the forum.
You should also contact forum member Lars, get a copy of his tuning and ignition papers and ask him about rebuilding your Q-Jet carb.
Do a search and read his current thread about a carb he is in the process of rebuilding.
Good luck.

 

With my build you have to keep in mind the engine compartment stays looking exactly as it does now. I'am sure 13s would be no problem, my combination works with the factory converter as well. When you lighten the bottom end like I'am talking it hits the converter in a whole new way, very snappy on and off type power. I don't like the extra stroke because your already cylinder head limited, but the 993/487 casting can be made to make power, on even par with a worked over Vortec head. The only reason I mentioned a build like this is because the car is so virgin. Please don't confuse me with looking for work, I have more than I can handle and the OP wouldn't like the price tag as Jebby mentioned earlier.

 

Mark
That was the route that I took for a 1970 L46, with the help of Mike Lewis. I bumped the compression up to 10.4:1 the cam has a late IVC of 76* ABDC. It runs awesome, even with an aggressive tune up on 91 octane I’m not experiencing any detonation. I couldn’t be any happier. Jebby your correct it’s the most expensive way to build a stock motor. But that first four barrel blast made it worth it, the motor pulls strong to redline.
Bob

 

Very nice!

 

I ma building a sneaky 355 this winter with the new Trick Flow "double hump" 175cc heads, Howards Hyd. Roller, 10 to 1, Performer EPS, Holley 670 Truck Avenger single feed (Much like an L-79 carb) and 2.5" rams horns......I expect this little guy to make 400+ horsepower and 440-450 ft. lbs. of torque.....going in a 69' Coupe with a Tremec 5 speed......should be as perfect a street engine as one would ever want.
Stay tuned for build thread coming in January......my first documented build thread.

Jebby

 

I look forward to it.