Alright the suspension and brakes are all redone and it drives great. It is time to tear into the tired L48. It is a 74 auto L48 and I want to get 400hp out of it on pump gas. You guys are the experts, give me a list of what to order and what to do. I plan to pull it out in January and do the build along with the tranny. The budget is around 3K can it be done, I also work in the auto industry and can get parts at a deep discount.

 

Have you thought about storing the old stock motor and buying a crate motor?

 

no, I like the idea of building the orignal. I do have a 350 4 bolt main in the shop that needs a rebuild also, if I'm going to pull it once I rather put the orignal back in.

 

as much as I hate to
I bought/built a 350 "R" engine that comes with Vortec heads, roller cam and 4 bolt mains
putting out @400hp well under 3k

 

I also like to build the motors. Crate motors are OK also but Ilike to do it myself. Heads are where the power is made. Save your money for a good set of heads and work from there. 400 HP from a 350 is aggresive but doable. If your budget is 3K for motor and trans I doubt it. For motor only you will be on a tight budget but with good shopping and your discount it can be done. Obviously headers and a good exhaust are going to be needed also so figure this into it also. You don't need forged bottom end if you stay conservative on the rpm and a roller cam is out of the budget. A good flat tappet cam in the 230 @ .050 range and good heads are going to be in the ball park of 400 HP. The only thing you will reuse is the block and maybe the crank. Crank kits are the way to go.

 

Stroke it.
But it probably wont last too long if your planning on running it hard. Seems like if your looking for 400 hp your planning on running it..

 

I thought about stroking it, I just want it to be a sleeper on the street and sound good. I would settle for 375hp right now it is a dog and anything would be an improvement. One thing I forgot to ask is how much stuff under the hood can I get rid of. The stock engine bay looks like a cluttered mess.

 

A 383 won't sound or look any different than a 350, and 400 crank HP along with a ton of torque is a pretty straightforward build. Like Gordon said, invest in some decent heads either way.

 

Id drop a 454 in it. You can do one cheep and get some easy HP and a ton of TQ. You would be happy..
Oh yea, I dont think a 74 Vette is going to pass as a sleeper.
As far as the bay, you can clean alot of that up (wiring). Also depends on emissions in SC. You'll have to ck that out.


GO BBC!!!!!!!!!!!!!!

 

I'll sidestep the crate-vs-overhaul discussion as it's been had many times on this board and elsewhere

How "stock" do you want your engine to be? Are you planning to stick with the stock intake, carb and exhaust manifolds?

3K will buy a performance overhaul of your L-48 assuming the block, crank and heads are usable. If your budget is "hard" at 3K I'd suggest going the 355 route. With the stock heads and manifolds, it's going to be tough to move beyond about 300 HP. A performance overhaul with some basic porting work on the '186-type heads, CompCams High Energy 268H cam and headers with a free-flow exhaust will get you around 325 HP at the flywheel and a nice fat torque curve from 2000-4000 RPM. IMHO, this is what you can expect to get for 3K. Going to a 383 won't buy much, as the build is flow-limited at the heads. Done right, this is a sweet engine with great street manners and plenty of "grunt".

Next step is heads and a bigger cam - but we're adding $1,500 to the build if we stick with a 350 (to about 400 HP) or about $2,300 if we move to a stroker (425+HP). My overall guidance is that budget drives the build - an engine back in the car and tuned correctly beats a "mondo" engine on the stand waiting for part$ every time.

Usage drives the cam selection, cam drives the heads, heads drive the overall build...and budget makes the hard choices

 

I just finished building my first engine on a budget and my advice is the same as others.

1. Spend your money on a good set of heads. I paid 300 dollars for my vortecs but then after i had screw in studs put in, my seats ground, and the surface trued, roller rockers, valve seals, retainers, keepers, and springs i had close to 1000 dollars in them. I could have gotten a good set of alumminum assembled heads for a little bit more than i spent. Or the same set of vortecs assembled for less than 800.

2. I got a good deal on my block, I bought a block, crank, rods, heads, and pistons for 500 dollars. I sold the the heads, pistons and rods for 400 and had 100 in my crank and block. I ended up putting 60 dollars in rebuilding a free set of rods from my neighbor, and 270 on a set of pistongs. If I did not get such a good deal on my block before, I would have bought a rotating assembly from summit that had rings, bearings, crank, rods, and forged pistons for less than 1000.

3. Make as much power as you can the first time around. Do not cut corners with machine work because you will regret it later. Do research to see what cam you will need to match your heads and rear end.

So to sum up what I have stated, Get a good set of new assembled heads instead of dumping money in old ones. Also, buy a rotating assembly that comes with everything like rings and bearings. This will be cheaper than doing it yourself.

I would suggest reading a book on motor building.

 

If you're set against the crate motor, I'd go with Popular Hot Rodding's "Danger Mouse" buildup. The nuts and bolts of it are Vortec heads, Performer RPM airgap intake, CC 268H cam, Demon 750 carb, and some 1.6 roller rockers. Made 427hp and 439tq.

http://www.popularhotrodding.com/eng...ine/index.html

 

Find a proven combo that makes the power you are after and build it based on that.

 

Not sure that I'd model my build after something that was specifically intended to be a dyno thrash "mule motor". It's a very hefty beast, but not sure that a full forged rotating ***'y is required unless you're making 450 HP+. I don't know if they published prices, but they must have 5K into the shortblock. There is more power to be found for less money - they made 504HP NA with some decent heads. I love the Vortecs and they're the best deal on the planet up to about 1.2 HP/CID, but they're not a high RPM, high HP head.

No pushback with copying a proven combo - just make sure the combo is designed to be used the way you're going to use it.

 

A stroker wil give you the most bang for the buck!!!

 

Here is a link!
www.ryanscarpage.50megs.com/combos1.html

 

I would agree that you don't need to have a fully forged rotating assembly to produce good power, and that they have quite a bit of money tied up into that engine. I would think that you could put together something very similar for a decent price that would still hold up well. Like I said, I think the "brass tacks" of the combo is the Vortec heads/intake, cam, and carb. Pair that up with a decent shortblock and good exhaust, and I think it would put out good numbers.

 

for relatively mild engines. The risk is always that the engine was designed for very different usage (trans, gearing, etc.).

I prefer to work from the usage/budget back to the build, as every car (and driver) is a bit different.

 

Big Block!

 

not to Hi_jack this thread.....but what mods are required for the changeover from a SB?