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So something else is going on there... The lights should "lock" in the up position with an over-center joint. To release them you have to reach up from underneath and pull the joint forward to "unlock" it.
I have Flotek heads on my ‘76. It also has roller rocker arms with 7.900” pushrods. Two years and many thousands of miles later I’ve had no issues with them. Here is my thread about installing them.
Angle plug heads should clear your rams horn manifolds just fine, but keep in mind you might run into issues if you change over to headers.
It is almost the same as an L82 cam specs but not quite. Top is 5200 RPM so power peak is probably around 4800. If you have an automatic, then any range of the power band under 2000 is wasted and this one starts at 1200. If you have an automatic, get something that has a power band starting around 2000. This cam works well in a manual shift heavier vehicle, like a full size or a pick up. Realistically, you should go to a roller cam due to lack of zinc in today's oils. No point in a flat tappet cam anymore.
While the engine is apart or out, CHANGE the front suspension bushings. The extra room will be appreciated. While in there, change to new brake hoses.
As black as those cylinders are, you are very rich, so you are losing power there. Looks like oil in there, but could simply be oil washdown from being so rich. Too bad you didn't know to do a compression test and leakdown test before taking it apart. Then you would know if the rings and cylinders were good or not.
On the engine, how much do you trust the previous owner? It is a shape to throw a bunch of new parts on top end to find out the bottom isn't up to the job. And it depends on money.
Have the block flushed out.
Check bearing clearances. Turn crank only if necessary.
Check cylinder walls for ridge, taper, out-of-round, and clearance. Bore only if necessary.
Get new rod and main bearings.
Get new rings.
Get a better cam.
Get new cam bearings.
Balance the assembly - crank, rods, and pistons.
Let the shop reassemble the short block. They probably do hundreds a month. Just get a good shop that will stand behind their work.
Get better heads.
Rebuild or replace the Quadrajet. or go to the newer fuel injection systems that are available.
All of this depends on money and your goals. Sit down, check prices, ask around, add it up. Make a plan and have a whole plan when you get ready to do it. Nothing worse than changing direction and finding out you need to redo things you thought were ok.
NOW
Once you have done all that, compare the prices to a crate engine from several engine places like Jegs, Summit, and others. You might be able to put a 330 to 400 hp engine package together cheaper than rebuilding and figuring our yours. And it comes ready to drop in.
There are "hidden costs" associated with aluminum head purchases that many are not aware of.
But first, yes you can use your old rockers.
ARP head bolt kits are a must. They come with a washer to prevent gouging into the soft aluminum bolt holes. ($130)
Most aluminum heads have the rocker stud pad located higher than stock. You will not be able to use stock pushrods.
You will need a pushrod length checker ($30) to verify the actual length needed. (This is done via the ink / witness marks on a valve-stem).
Figure around $140 for moly rods for guide plates, one-piece units for durability and usually 0.100 longer custom size. Check cyl head owners manual.
Next, gaskets. No $40 a pair here. You have dissimilar metals, each expanding / contracting at different rates. Make sure your gaskets are compatible with this type of match up. Figure around $45 EACH ! not a pair.
You will need "long reach" sparkplugs. The hole is thicker than stock.
Think long & hard about angle-plug heads. Mostly a sales pitch for a few more horse, but at the cost of misery with plug-wires burning on headers.
And last, someone mention roller cams because lack of zinc in oils. That was a decade ago. Tons of oil brands have lots & lots of zinc. Not an issue anymore.
The difference between roller cam kit and flat tappet kit is around $800 when all said and done.
Compression makes Horsepower. Get rid of the low compression pistons and bump it up and your tires will be a spinning....
Aluminum heads simply flow better because they are a newer design than the 1970's design of the Corvette heads. I run 12.25-1 with cast iron heads and have no problems. I am using the 1968 L88 heads but the exact duplicate made of cast iron versus the aluminum versions used on L88's and L89's of that year. 1968 Corvette used a closed chamber cylinder head that reduces the issue with detonation.
The issue with Numbers Matching engines is that today anybody can re-stamp an engine with whatever they want to put on the block. Numbers matching means nothing to me anymore. I like to see the date codes as they show a more real story of the engine's history.
The engine in the advertisement looks nice but I am leery of companies that build them. They have to make some profit someplace and I would like to know where. My engine builder and I agreed on what his fee would be regardless of the engine's cost. His fee was set in stone so he had the profit taken care of. No "compromise" parts would be used and all the paperwork and receipts were kept for proof.
Watching someone build an engine for you will get you will familiarize you with the parts and how they go together. Instead of buying pre-asembled heads we used old cores and rebuilt them after they were ported and cleaned up. Every part was replaced and they were better than new when we put them on the engine.
I would suggest that you find a local engine builder and work out a deal with him or her to build you a new engine from the ground up using your original parts to keep the cost down. My engine builder was an older guy who worked on Can AM race cars back in the day. He knew a lot of tricks on how and where to find hidden horsepower. My engine block was painted inside with Glyptal Epoxy paint to help the engine oil return to the oil pan as quickly as is possible. There were many tricks my builder taught me while he was building my engine and I was impressed with his patience in setting up the internals.
With the engine out and mostly torn down i would seriously consider a freshen up on the bottom end unless you put enough miles on it to know it wasn't burning oil from worn cylinders.
Pat
Thank you for all of your replies. So much info to go through. I did reach out to an engine builder called Skip White Performance. They said for an engine around 350 HP it would cost me approx 9K. That's much more than I wanted to spend. So I started looking at heads and I saw these cast iron Vortec heads by Deepwater 170CC 62CC - Some of you folks recommended 180CC 64CC aluminum heads. Is there a big difference between the 2?
I had Flotec heads with Doug's headers P/N 350D. Angle plugs is what you want with those headers or ones that are similar in shape. The stock rockers arms don't clear the valve springs of the Flotec heads. Below are pictures of Flotec heads with Doug's headers.
Last edited by Fly skids up!; Jun 26, 2025 at 08:15 PM.
They’ll fit on any year up to ‘82. Websites usually only list up until ‘74 because that’s the last year of non emission compliant cars catalytic converterly speaking. All small block headers will work on any head too, you just generally want to make sure the port shape is the same.
Doug’s headers and side pipes on my ‘76.
Last edited by Piersonpie; Jun 26, 2025 at 09:30 PM.
It is almost the same as an L82 cam specs but not quite.
Make a plan and have a whole plan when you get ready to do it. Nothing worse than changing direction and finding out you need to redo things you thought were ok.
That 260H cam ain't much like an L82 cam; and that's a good thing, especially since this car has an auto trans.
L82 has about 222-224 degrees @ 0.050" duration both I &E. This 260H has about 216. This 260H has nearly ten degrees less duration and that'll make this much more responsive IN Traffic on street where it'll live most of its life. If those lobes & lifters are in good shape; keep that 260H. Several of the most popular cam brands make same profile; it's a good one. Those pistons look similar to L82 or '71-up LT1 pieces; they're flattop with a trough & that's not unusual at all. They may be forged; if I could see underside of em, I can tell.
Originally Posted by OmegaRoger
I don't trust the guy that sold me the car. He already got caught lying saying the engine was original to the car.
What do you think about this crate engine from Summit Racing - It's in my price range as I wanted to be around 4 to 5K for an engine build.
ATK (aka ATK Vege) is bottom of the barrel; run.
If you can up your crate motor game another $1200, I suggest GM P/N 19433032 . 350ci/357hp every bit is All Brand New and All USA with best Warranty (GM) anywhere, anyway. Good genuine GM iron Vortec heads, good steel billet roller cam & roller lifters, good forged steel crank.
The 260H cam was replaced with a COMP Cams 224/230 Hydraulic flat cam. Pistons are out being cleaned and will replace the rings and bearings. I'm going to ball hone the cylinders and put each piston back into the cylinder it came out from. The piston connecting rods have marks on them (dots) 2 dots for cylinder 2, 3 dots for cylinder 3 etc. I didn't do this they were already on there so I assume someone else has been in the engine and did that. SO far I removed the front suspension and installed new bushings and ball joints. Put in new shocks and new rotors and brake pads. I had to drill out the rivets in the old rotors - wasn't too hard to do. Now I'm focusing on the power steering. I will most likely rebuild it rather than purchasing those complete kits you see on line. I heard some of the new hoses tend to leak. Once I'm done with that then I'll focus on getting a new radiator, AC condenser and compressor. Once I'm done with that ill finally get the Flotech 180/64 heads I was looking at and then decide on a new carb or EFI - cant use my existing Rochester carb as it was dropped and cracked.
When I see crate engine pictures like above, I think about all the parts the customer has to pay for and later on have to remove.
Why? Some parts won't work well in C3s.
The Intake is likely too tall for a C3 hood.
The oil pan will not likely clear C3 steering linkage.
The waterpump is likely GM fits all SBC. But will not work on C3s.
The heads have small valves.
The heads will only accept limited vortec Intake bolt pattern options.
Seems to me, a wiser purchase option would be to start with a nice "short-block".
I haven't been on here in awhile, just saw this. Below are some chassis dyno test results from a 350 El Camino I had several years ago. The motor was a base 350. It had an Edelbrock Performer EPS intake, a set of generic headers, and a mild cam (never determined which cam it was, but probably a Comp 260 or 268.
I first added FAST EZ 2.0 efi & ignition control. Tuning was super easy with it, and after several dyno pulls I got the blue results (bottom curve) on the graph. The Elky ran lower 15's at the track in this form.
Awhile later, I came across a set of Edelbrock E-Street aluminum heads on eBay - CHEAP! They were the larger chamber size, and I got them for about $700 shipped! A friend is a highly respected head porter, and he offered to give the heads a quick check. He re-honed the valve guides, as they were tighter than he liked. He also did a quick back-cut on the intake valves, and we changed out the seals. I then installed the heads, and took it back to the dyno.
The middle (purple) curve is the first pull, with the EFI settings the same as with the iron heads. AFR targets remained the same, but I started playing with the timing. As expected, the aluminum heads required less total timing. Also, the new heads liked the total timing to come in quicker. The top curve is after I finished tuning the timing. Bringing the total timing in at lower RPM resulted in a nice boost in the mid-range power. This was all done on 87 octane gasoline.
Right now, I'm working on a friends '72 350 Corvette. I initially installed some AFR heads, Stan's Tri-Y headers, a HR cam that I designed (and had ground by Comp), and a nice 2.5" exhaust system. Some details and photos here: https://www.corvetteforum.com/forums...pressions.html I'm not sure of the gears, but it would easily smoke the tires.
Right now, I'm finishing up some updates to that car. I just installed a FAST EZ 2.0 efi & ignition system on it. I took it on a test drive yesterday, it chirped the tires pretty hard when it shifted into 3rd at about 5800rpm! I'm hoping to put it on the chassis dyno next week, but it is obviously much stouter than the El Camino.
