better performance

[Les Walter]

for a stock 1973 350 engine with 190 horsepower, the order of things to do to get better performance appears to be:
1. Change from points to electronic ignition
2. get the exhaust to breathe better...headers
3. change carb, intake manifold, and cam
4. higher compression heads

The engine has 66K and smokes a little on start up when cold
Rear main seal leaks a bit
I get 12 mpg locally.....never had it on a trip yet

I'm not after anything fancy or gaudy....I've had the car 6 months now and want it running well and dependable....working on the brakes now

Am I far off??

Les

 

[Glensgages]

Am I far off??

FAR-OFF from what?

More precisely, what are YOUR goals for the '73?

I'd think that getting it to run better, AND get better MPG, wouldn't be too-hard;
what are your realistic expectations for the car?

 

[wallyknoch]

All of the above will definately help, the correct combination is what you have to strive for. Bigger is always better, but the parts selection has to be compatible with each other or you will waste a lot of money and still have a poor running engine. Target where you want to be and buy the appropiate parts to get there. Just pure money will buy all the parts you need, however they have to work together.

 

[The73vetteman]

I have a 73 with the L48 - I assume this is what you have - and a previous owner had changed to headers, Edelbrok manifold and Holley carb. I get 9 - 10 mpg around town and although I haven't dyno'd the car the performance is less than startling.I think the key to higher performance is better breathing. I'm not sure that electronic ignition is really going to make much difference.

I plan to change the cam at some point, but right now like you I'm working on the brakes. For some funny reason I'm more concerned about being able to stop quickly than go quickly.

I don't know if this is much help. As Glensgages said, it all depends on what you're trying to achieve.
'73

 

[wishuwerehere82]

Here's a cool tool that I heard about on Pat Goss's program.

http://www.proracingsim.com/

Choose your parts, and run the simulator to see what they do!

 

[Tweek]

Les, watch the high compression heads on a 66,000 mile lower end! I did the samething on my 350, seems the added compression soon turned my lower end (rings) into an oil munching beast. After about 1000-1500 miles on my top end rebuild it started to drink oil and smoke pretty bad, I ended up pulling the motor and doing the hole thing. It was a lesson well learned for me.

Ron

 

[Bob Chadwick]

Before changing components that increase the strain on the engine, you want to get a leak down compression test to make sure the internals are in good shape.

 

[Les Walter]

Thanks for the replies.......I don't know the history on the engine and had planned on removing it to replace exhaust gaskets, redo the rear main seal and pan gaskets as well as the front pulley seal. My questions stem from the question about what to do while it was removed and how far to go and what upgrades might be worthwhile. I'd plan on new bearing inserts and have the heads looked at. I realize that there are trade-offs when modifying but is I can gain by what others have done...good and bad. I will not be pushing this thing very hard....I can buy a lot of gas for what it might cost to do some changes and then be disappointed in mediocre results

les
les

 

[Vettehead Mikey]

Electronic ignition will gain you zero HP. Your stock Qjet will get you as much HP as any aftermarket carb, your stock intake is about 95% as good as anything out there. The stock exhaust manifolds and exhaust are more than good enough for 375 horse.

Don't waste money on replacing any of the above and don't get sucked in by what you read in Jeg's or Summit catalogue.

Go after your cam, heads/valves and compression. Do a little research on early 70's LT-1 engines, that's about the perfect combo for the street.

 

[curtis]

Les, Whatever you decide, consider that your old shortblock is near to being refreshed anyway so why not go ahead and bore, drop in some hypereutectic pistons, new timing chain and gears. All that runs about $600 around here if you pull the motor yourself and also reinstall it. Seems to me fixing up the top end only still leaves you with a 66,000 mile motor instead of a new one. I'd guess that with heads, cam and block work you will probably spend about $1200 and have a decent amount of power and reliability. Vortec heads are cheap power, but you also need the intake to match.

 

[78SilvAnniv]

I would recommend rebuilding/freshening the entire engine or not doing it at all and buying crate engine that is ready to drop in and go.

We just went through pulling my engine twice within 5 months (mistake on our part) and replacing the heads and cam. For the amount of money spent (parts and special tools) and time lost we could have purchased a 400-500hp crate engine.
Our mods will put us around 350hp, and I am happy with that. Another plus is that I know our mods will work efficiently together...but we did over spend our original budget.
Heidi

 

[Bob Chadwick]

...but we did over spend our original budget.Heidi

Heidi,

What were you thinking? A budget when working on your Vette. I've never heard of such a thing.

 

[78SilvAnniv]

Kenny was reading over my shoulder, and I heard him mutter:
"It was all worth it, just to get the tools!" :J

I can't do anything with him, he's a lost cause.
Heidi

 

[Bob Chadwick]

Girls = Shoes
Boys = Tools

Can't be explained any simpler than that. :L