midnightrider80

Curently I have an l48 in my 1980 vette. I have since got an overhaul 700r4 with 220o stall to put in the car. My plan is to take the motor and trany out the top to do the swap (has not happens as of yet). Thoughts and plan have been evolving on what to do with the motor while it is out. The car has 42,xxx miles on the clock as far as I can tell (has an aftermarket costum corvettes 140mph speedometer in it so can't be 100% sure what the actual miles are). The motor runs fine, just not a lot of get up and go as most vettes from the era. The car had a turbo on it at some point, but was removed two owners before me (>14 years ago). A local machine shop has recommended to put on some Patriot aluminum heads, change the cam and consider a different carburetor( currently has an Edelbrock 650 and Edelbrock performer intake). Said he sells the patriot heads after doing some work on them himself for $1,200. So with that and a cam I would be at about $2,000 put together assuming he doesn't find anything wrong when the heads are pulled.
Found another person with a zz4 motor that he claims has under 3,000 miles that he got from someone that owes him money, so never heard it run or anything along those lines. Motor doesn't come with starter, plugs or wires. He wants $2,750 for it.

I am stuck on which rout to go with since there are unknowns both ways. My original goal was to have just north of 300 hp in the car, so not looking for huge hp, and wast to be very streetable. It gets about 500 miles put on each year, but that may increase if it is more fun to drive.
Sugestions on what my be better for me would be appreciated. Also, if I take the motor out to set it aside, what's the best way to store it? It is mathcing numbers for the car.

Redvette_22

What "work" will the shop do to the Patriot heads, and are they new to start with (I thought they were bought out a couple of years ago)? I had a set of Patriot LS heads on my 03 Vette and after about 1300 miles, and 20 or so drag strip runs, they were sent out to "update" and they were scrap.. Depending on what "work" was going to be done "after the fact" I think I'd consider a set of the Summit Racing aluminum heads. They are just about $1000 for the pair and in your case most likely don't need any additional work.

In my case, 72 L48 auto, I am currently looking into taking it to a 383 instead of an overbored (.030) 355 CID and there are many options. If you plan on going to a "bigger" cube engine & you have the ability to assemble it, there are a number of options on Ebay where a complete shortblock is $1900 +/-, but you must assemble it.

What are your "end game" plans for your car?

midnightrider80

Don't remember exactly what was included in his labor on the heads, I think it was checking different specs (because he didn't trust the manufacturers to get everything 100%) and boll blending.

The end game is just to have a respectable amount of power in an easy to drive car. We purchased the vette just before our wedding where we surprised everybody by taking off afterwards in it about 13.5 years ago. Since then not much has been done with it and always thought it seemed slower than my 88 turbocoup thunderbird. Right now around 300 hp seems respectable, and at this point don't plan to try for much more. Putting the overdrive in so I am not at 3k going down the interstate. We had thought about taking the car out to the west coast sometime and would want it reliable enough to make the trip.
Unfortunately I am not confinate enough to put a motor together. I have tried setting valves in the past, but never seemed to be able to do it correctly. Was hoping to be under $3,500 for the power train, with about $1,000 in transmission, leaves about $2,500 for motor (the zz4 motor would be putting me higher than this). Also may be doing body work in the future, but that will be years down the road probably. We probably will never be selling the car, but also don't want to devalue it either.

TedH

There really is no chance you can devalue an '80 L48. They were underpowered from the factory and 1980 was one of THE highest production years for the C3.

If you have access to friend(s) that can help with engine removal and re-install, get the following crate engine from Summit:
https://www.summitracing.com/parts/n...9529/overview/

Have a tuner rebuild/recurve your HEI distributor to take full advantage of the crate engine. If you want to do it yourself, get Lars' papers from this site on how to tune your distributor for performance. Ditto for your carburetor.
Have the carb tuned accordingly. Add K&N filter.
If you haven't installed good turbo mufflers, get them. I favor Dynomax Super Turbos.

You will get an honest 300hp from this swap and spend right at $2,500 in parts.

If it were me doing this, I would do the following:
Buy the summit heads OR DART Iron Eagle heads with 64cc chambers and 180cc intake runners. Both are right around 1,000 for pair.
Buy an engine rebuild kit with .030 over pistons, nice hyd lifter cam kit and all the seals, bearings, etc. needed to rebuild the engine.
Tear the engine down and have it bored .030 over, the new pistons hung on the rods and the block prepped by a machine shop.
Get good tools to help with the work and enlist the help of friend(s) experienced at this. Learn from them.
Buy a rebuild kit and rebuild your HEI distributor and lay a recurve down on it
Assemble and re-install the engine
Tune/rebuild the carb for performance
Get good Turbo mufflers and update the exhaust.
You will have $2,500-3,000 in parts and tools but you will learn A LOT in the process.

See my sig. This rebuild above is about where I was around 2004. It put an honest 225hp to the road with 289 torque. Lots of fun and very lively with the 700R4 and 3.54 gears. I have since added the roller cam kit with fresh cylinder head rebuild (2014). Lars rebuilt and tuned my quadrajet for performance back around 2004 and I haven't changed a thing; it runs perfect. I had a tuner with a dyno curve the Accel Performance HEI distributor. I have Jet Hot coated hedmann, true duals with h-pipe and Dynomax Super Turbo mufflers. I would guess the engine can put close to 290hp to the road now. That is in 350-375hp range at crank.

jb78L-82

The 290 GROSS Hp summit engine referenced above would be a cheap way to get the L-82 225/230 NET HP in your 1980 since the cam specs for that crate engine are the exact L-82 cam specs. Add in a few of the accessories mentioned by TedH above and you would be close to an honest 275-280 NET HP, in today's world. Not Bad..........

lvmyvt76

put a crate motor in and save the original motor for any future owner.

Aggitated Monkey

When I pulled my L48 from my '78 to install the 383 I traded the L48 for a Rugar New Vaquro .45 long colt.

ykf7b0

I have the original L-48 in my 76. I removed the factory heads and installed some 98 Silverado Vortec heads, Hooker ceramic coated full length headers with a new 2 1/2 exhaust system, rebuilt the quadrajet with the help of Cliff Ruggles, and rebuilt the distributor. All this really woke the lazy L-48.

Kacyc3

I wouldn't even consider that engine for 2700 it may be junk and you wont know till you $ is gone. You say this engine had a turbo on it years ago, this tells me the person that did that either put some money into the engine to prepare it for the turbo, or gambled and risked blowing up a running stock engine, either way tear it apart and see how it looks. If its trashed then you can but that new crate motor mentioned above or rebuild yours as a back up plan.

midnightrider80

Am leaning more and more not to get the zz4 motor, I don't know the guy that has it now, and he won't give me the number of the guy that had it before.

Aggitated Monkey

In all seriousness I would not buy a used engine from anyone I didn't know well or trusted or wasn't on this forum. Many people have been ripped off with used engines as there are a lot of dishonest people selling them all cleaned up with new paint. I couldn't sell my L48 and that is when I traded it for a gun.


Heads and cam on your L48 will wake it up. 64cc chambers will increase the compression. If your bottom end on the L48 is good then I would go in that direction.


A warmed up L48 with the 700r4 will make a very nice driving car.


Good luck.

Redvette_22

I would agree on this, the used ZZ4 engine is not a good deal, and I'd stay away from the Summit long block and do what my buddy did to his 79 Vette. He bought NEW GM Vortec heads (with the higher cam spec mods) and intake (using a 750 Holley carb) from Scoggin Dickey, a somewhat mild Comp hydralic cam, installed the "least expensive" long tube headers from Jegs & a 2800 stall converter "house brand", from Jegs and used the factory exhaust & stock rear ratio. Those mods took him from a "stock" 15 second car to a mid 12 second car, and still have total street manners ( he also drives to and from the track). I don't think he spent $2000 on the entire setup, although it was a few years ago.

I forgot to mention that none of the aftermarket parts have had any "extra" work done to them, they are truly "out of the box" parts.

lvmyvt76

but you don't know if your L48 bottom will hold up to the new parts, and how hard you can push the old engine. a new crate motor will have a warranty if problems arise. I don't know how hard you are going to push the rebuilt or new motor, usually you are going to test it some!

JohnnieUtah

What I would like to know is how can you tell if your bottom end can take a set of new heads and cam. I've been wanting to know this for a long time.

jb78L-82

Start with a compression test on all cylinders...............

lvmyvt76

even after doing all the testing you can with the engine together, it still might survive. Thats why a crate motor with warranty is the way to go. Put the original in the corner of the garage, or have it rebuilt instead(no warranty usually).

tyancey00

I have an 80. I have been where you are. I can not say this enough times,, Buy the crate stroker, drop it in the car and drive the wheels off it. You will have a lot of fun and almost no headaches. Do a new aluminum radiator at the same time. Just suck it up and do it and then in the spring when you light it up you will have a hard time wiping the smile form your face. I went the other route and that is why I say this. Life is too short to chase a half *** rebuild. Do it once and be done!!

7t9l82

I agree the zz4 is a giant risk I wouldn't take.I'd like to see what's been done to your existing engine and I get a good vibe from what your machine shop is telling you. That may be a good option but your going to have to check it out.

77Driver

I'm thinking about doing some of the engine updates too. Wondering about the radiator Yancy. Is it a 3 or 4 row? Without any changes today my 3 row on an unmodified L48 does not keep up with it at hwy rpms. Without wishing to get into a radiator diagnosis just wondering what you selected and how well it works. The two subjects really go together.

Kacyc3

how old is your radiator?