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I was recommended to post here to share my good results with the hive mind. I bought my wife a 1980 base model 350/auto c3 for her birthday last year. It’s really hers not a nudge wink- I’m 6’3” 275 and while I can enjoy driving a c3 they are not dignified to enter/exit and my head touches the roof etc.
I’ll try not to write a novel here but it had 90k on it and drove well but typically underpowered with good grunt off idle and that’s about it, no real hp. It’s a corvette though and she loved driving it. We did have the trans rebuilt with a mild shift kit and stock converter last year.
Recently it started pulling the #2 intake rocker stud. Scary noises, simple fix. I told her we could be careful about metal shavings and just install a screw in stud and it would be back to just how it was …or take it as a sign that now is a good time to throw some heads & a cam at it! She jumped at the chance for us to work together and make it quick. It was hard to not keep saying “move let me do it so we can be done before snow falls” and a lot of stuff she doesn’t have hand or upper body strength for like torquing head bolts in awkward spots, but she learned a lot. And I tried to be patient while feeling the usual frustrations of hard dirty work.
So here’s the debrief- I think I selected a great combo and I’m super happy with how it came out. The goal was to maximize power while keeping iron manifolds, stock rear gears, and keep drivability. So, mild hotrod. It already had a well tuned eddy 650 and I had thrown turbo mufflers on the 2-1-2 system with a cat, but it had an adapter for the squarebore carb which isn’t ideal. Also I had put on a new HEI with MSD coil & new wires before I gave it to her.
We managed to avoid project creep- the cyls had basically no ridge with 90k on the motor, oil pressure was good, existing water pump was good, already had O-ring water neck, exhaust was leak free.
We installed a performer EPS intake with small 12pt head bolts and a thin cheap heat insulating block under the carb, a howards retrofit hydraulic roller cam CL110245-10, 7.200” pushrods, large slot stamped rockers, AFR Enforcer heads OOTB that came with guideplates and ARP rocker studs, new head bolts, and that’s about it.
The cam is listed at 1600-5400 rpm operating range with .500”/.510” lift and 225°/231°@.050, so not radical but I was worried it would be soft on the bottom because they recommend a 2500 stall. The closed chamber heads brought CR up to around 9.2 so that probably helps.
The car idles nicely and there’s a touch of lope but nothing crazy. You don’t have to idle so high that it clunks into D and tugs forward at lights. It has good street manners.
The stock off idle grunt is slightly softened but once you’re going the midrange is way stronger and it’s decently quick. After a little driving she won’t miss the little bit of grunt she lost out of the hole. Once you’re cruising a stomp kicks down a gear into the meat of the power and the car pulls hard while making glorious v8 noises.
Overall I think the tradeoff was worth it, plus if she gets bored there’s room to grow with headers into 2.5 duals probably offering at least 15-20hp and a converter swap offering holeshots and instant power. But for now I’d say this combo was easy, under $3k, and probably puts 250hp or better to the ground.
Last edited by Radarsonwheels; 10-11-2023 at 03:30 PM.
Atta girl, headers and actual dual exhaust will give you more than 20 up with those new heads and cam
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I'd say something other than that edelbroke carb would help if you have the stock intake change that too. Good job. Also get your distributor set u.
Very good job!
Get the headers and pipes on it and it will be a different engine......way more than 30 horsepower to be had if you are running the stock exhaust....you are choking it pretty terribly.
Think of power as a result of being to get more air in and out of the engine.....you managed to get it in there, a LOT more in there......but now the exhaust is even more restrictive because the engine is trying to force more out the same hole.......
I used that exact cam and intake on a 357ci small block with Trick Flow heads at 10.6 to 1 compression and it is probably one of the best running street small block 350's I have ever built......but it has a real exhaust.....
By my estimates with your parts...stock system is holding you back about 50-60 horsepower.......
Do you have a proper timing curve on this?
Good job on the makeover......good to see folks out there getting after it......
Atta girl, headers and actual dual exhaust will give you more than 20 up with those new heads and cam
.
I'd say something other than that edelbroke carb would help if you have the stock intake change that too. Good job. Also get your distributor set u.
Very good job!
yeah I put long tubes on everything but she thought it was fast & fun stock so it’s amazing now. I know how much fun headers are 😉 to install and then even with good soft aluminum collector gaskets you have to stay on top of them sometimes.
If it was my car I would have started building a forged 10.5:1 383 with long tubes as soon as I got it 😂 maybe a tunnel ram or 6-71…
Get the headers and pipes on it and it will be a different engine......way more than 30 horsepower to be had if you are running the stock exhaust....you are choking it pretty terribly.
Think of power as a result of being to get more air in and out of the engine.....you managed to get it in there, a LOT more in there......but now the exhaust is even more restrictive because the engine is trying to force more out the same hole.......
I used that exact cam and intake on a 357ci small block with Trick Flow heads at 10.6 to 1 compression and it is probably one of the best running street small block 350's I have ever built......but it has a real exhaust.....
By my estimates with your parts...stock system is holding you back about 50-60 horsepower.......
Do you have a proper timing curve on this?
Good job on the makeover......good to see folks out there getting after it......
Jebby
I told her that she should enjoy it and get used to the power. In the meantime we can make sure the existing tune is sharp and no leaks come up, get a re-torque on the downpipes etc.
I also told her the next upgrades in order of ease would be a recurve with softer advance springs, making it a true dual exhaust with a deleted (cough-cough) or cheap hi-flo 2.5” cats by removing and replacing the existing X pipe/cat situation, a 2500 stall converter, and rear gears around 3.55 or 3.73.
Shorty headers and a dual 2.5” system would be nice, long tubes even nicer. I haven’t looked into sidepipes- she doesn’t want to have hot stuff around our clumsy kid (or herself…) so probably not. Also she liked when I swapped the stock mufflers for cheap turbo mufflers but she’s not into a loud exhaust and definitely wants zero drone- she would probably hate flowmaster 40s or long glasspacks that I would love.
Oh and of course there are practical issues to solve- the connector on the passenger window switch is bad so I ordered a new one, I got the tach working since it wasn’t and ordered a proper connector to clip into the HEI for batt/tach since the clip is broken on the batt currently and the tach is a home made extra wide female spade, ordered a new 3/8npt water temp sender which will hopefully fix the last not working gauge other than the clock… and the heater hose was looped when we got the car so I gotta assume the heater core leaks and we’ll need a whole day of cursing and human origami to pull the hvac box.
But in the meantime the car is actually respectably quick and the gas pedal is fun instead of boring, and there’s some room to grow with bolt ons.
Long tube headers aren't a burn risk unless you are confusing them with side pipes. Headers and a good exhaust will impact fuel economy in a positive way unless she always drives it hard.
Long tube headers aren't a burn risk unless you are confusing them with side pipes. Headers and a good exhaust will impact fuel economy in a positive way unless she always drives it hard.
yeah that’s why I said I didn’t look into sidepipes- the hot pipes & shields.
Like I said about headers- I’m a believer! I put headers on all my hotrods I even put 1 5/8” long tubes on my last 1980’s full size suv. I’m mostly shy to do it on her vette because of the expense and because I have done lots of them where you have to lift the engine or ding tubes or whatever they’re just a pain sometimes to install. Then you’re burning plug wires and re-torquing the flanges and it always seems like the collector gaskets need attention. For her needs the low maintenance quiet ram’s horn iron manifolds are great!
I do like the idea that we have room to add HP and sportyness with timing, exhaust, stall speed, and gears if she decides she wants more. She digs more power but mostly likes cruising while blasting Dio or Van Halen and surprising people when it’s a lady and not a retired gentleman driving a cool older car.
10-11-2023, 01:47 PM
Successful top end swap >$3k on 1980 base 350
