Shark Racer

FYI - the 260hp engine is essentially identical to the L-48. Heads are the same as a late 70's smogger. Cam is the same. Compression is rated higher but actual measurements have proven it to be lower than advertised.

The only horsepower increase you'll see going from a used stock motor to the Goodwrench 350 is from whatever wear and damage there is to the original components.

I made the "switch" in 2000 expecting a big horsepower gain. Back then, the 185hp L-48 was what I was used to running, and I couldn't tell a difference between the two engines.


You will be gaining something by putting the GW350 in - a new engine with no miles and no head problems. Horsepower, torque, only what you're losing from your current engine problems.

If the bottom end of your engine is sound, going with a reasonable set of aftermarket heads will give you a lot of horsepower and torque, and really transform the ride.

jb78L-82

Its for this reason that I constantly harp on the Gross versus Net versus RWHP band wagon-crate engines are rated as Gross HP and all production cars (engines) since 1972 have been rated as NET-big difference.

A 260 gross hp crate engine is about 190-200 Net HP.

REELAV8R

If I wanted to keep a car stock for whatever reason, but still wanted more power, I would pony up for porting of the original heads, raise the compression, put in a good cam for that combo, and port the intake manifold. Hog out the eshaust manifolds and put in true dual exhaust. Then get better bottom end components like the crank, pistons and con rods.
Then it would be more powerful and far better version of it's original self.
It would cost more and not be as good as modern heads but still original enough that no one would know the difference from looking at it.

Bloodzone

I wouldn't worry about a numbers matching engine on a 80. I have a 79 and did a 383 crate upgrade and gave my old L48 away. The L48 had a blown head gasket which made it a little easier to let go. If I had a 69 with a high HP original engine it would have been different. To me, a low HP later model C3 motor with 190HP is not worth saving. But thats just me, I may be wrong.

samdjr74

This may be a good choice as well but here's my concern. I don't know the condition of my bottom end but I have no reason to think it's bad. The problem is once you open up a 35 y/o motor what else will break all of a sudden? But I'm open to suggestions, if I was going to go this route, what heads would you recommend? Again, high horsepower isn't a requirement, reliability is.

Shark Racer

Without playing with the bottom end, I'd look at one of the smaller runner heads, like a 180cc AFR. The heads would cost nearly as much as the entire GW350, but you'd still have to do valvetrain and I'd go with a (slightly) more aggressive cam.

Vortecs are a great choice and you could get a full setup, with intake and cam, for under $1000 I'd imagine. It would definitely wake the motor up and for the kind of cam I'd want to run on the compression an L-48 bottom end offers, the heads would be more than sufficient.

I like the AFRs for a lot of reasons though:
1. When the time comes to build another bottom end, you'd be ahead of the game and only have to refresh the heads.
2. Weight savings.
3. My sense is that they run cooler than iron heads, but that's just inuition and not science.
4. Stemming off of (1), not only do you have the performance delta but the AFRs are ready to run with bigger cams out of the box. The Vortecs will need machine work to accept springs that support cams with > ~.450 lift.

I quickly looked at Trick Flow 175s as well, which end up right about in the middle and could probably come in about the same price, with cam and valvetrain, as the engine combo.

Performance wise, at low lift they hurt a little vs the vortec on the intake side but are much better on the exhaust side. At .400" lift, they cross over and beat it on both sides. You get an aluminum head, which is definitely nice, and you could probably run a bit less of a split on intake vs exhaust duration on the cam grind.

You'd be happy with any of these. I'd go down the AFR path myself because I can't leave well enough alone.

If you know yourself well enough to know that you're not the kind of guy to start chasing HP numbers, then I think the vortecs are a good bet. Just be mindful of the cam choice so you don't overdo it on lift.

brick1234

Swapping an engine to make the overall car better in performance is the quickest/cheapest way to go. Even finding a used engine is a better option if your a gambling man you never know what you will find. Out of the 3 cars I have 2 that I have done engine swaps and looking at doing the 3rd one (1980 L82) but with BBC with aluminum heads vs a sbc.