350 to 383. Is it worth it?

[Sklptrljay]

So in the next year or so I'm contemplating making the upgrade from a 350 (rv cam/ Holley/ Edelbrock intake) to a 383 with a similar setup and maybe some aluminum heads and Vortec setup. I bought the truck with the current drivetrain and it's ok, I guess. It runs pretty well, but it lacks oomph, if you know what I mean.

Has any one done this?

Is it noticeably better?

Does it in your opinion, justify the expense?

[adricar1]

Building a 383 is not a great deal more than a 350 if you build like for like.If the crank needs a grind then the cast 383 cranks are not much more. Rods pistons etc are similar prices, where it gets more expensive, when you buy light weight forged pistons rods etc and a forged steel crank. Yes you can feel the difference, i would go 383 every time over a 350. more torque.i have built many 383s and i prefer the 6 inch rod combinations over the 5.7 inch rods.Good luck, the parts in the usa will be allot cheaper than i have to pay with all the taxes and freight.

[special-K]

Big Block freaks will probably have something to say, but in my mind doing the 383 is like converting your small block to a big block...as far as power characteristics. No, it's not the massive casting or similar in design, but you will gain a noticeable muscle gain. From the bottom up you can build a hella strong small block and using these heads will expand that all the further. The cam used and compression ratio is another factory, but just a mild stockish 383 will be a noticeble improvement in power. You're only 17 cu. in. lower than a SBC400 and those thing stock are night and day in bottom end from a 350. Adding stroke is a truck thing to do. it is the one single best thing you can do for power improvement in a heavy vehicle. Gotta get that mass off it's haunches.

[bbcmudtruck]

Big block freaks unite hahaha! I think I understand what your saying here and that is adding the extra stroke and CI will increase the torque, which is what turns your tires. Although you won't get big block torque, you will see a pretty good gain. You can build a fairly budget friendly stroker depending on the condition of your block and what you'll be able to reuse. Have you decided on a budget yet? Ultimately, your budget will determine your power output. If your just reaching for a 400hp/400tq motor, it can be done with a $5000 budget or less. Again, it will depend on how much you'll be able to reuse from your old motor and the condition your block is in. Machine work can really eat up a budget with a quickness.

Of course, if you have an opportunity to pick up a running and complete BBC, I'd go that route!

[Heavymetl]

Given the goals and condition of your current 350, a 383 may not even be needed. I'd imagine a low compression 350 with "RV" cam, smogger heads, and an Edelbrock Performer slapped on the top with 3.08 gears is an absolute dog driving at any speed.

A set of aftermarket heads (or even Vortecs w/new intake manifold), a properly spec'd cam (don't go too big) and the addition of your singature mentioned 700R4 and 3.73 posi will make a WORLD of difference from your current point.

Yes, a 383 will make more torque at a lower rpm than a 350 with the same induction system, but that's certainly not the first place I'd look for more power. More cubes take more air, and more air takes more money...

[cooperhw]

Originally Posted by Heavymetl

Given the goals and condition of your current 350, a 383 may not even be needed. I'd imagine a low compression 350 with "RV" cam, smogger heads, and an Edelbrock Performer slapped on the top with 3.08 gears is an absolute dog driving at any speed.

A set of aftermarket heads (or even Vortecs w/new intake manifold), a properly spec'd cam (don't go too big) and the addition of your singature mentioned 700R4 and 3.73 posi will make a WORLD of difference from your current point.

Yes, a 383 will make more torque at a lower rpm than a 350 with the same induction system, but that's certainly not the first place I'd look for more power. More cubes take more air, and more air takes more money...

I agree. If you are going to change gears anyways do it first. Just changing for 3.08's to 3.73 you will notice a bunch of get up and go. If you drive high speed down the freeway it will buzz a little higher. That's where the overdrives shine. lower low and overdrive.
Then wake that motor up.

[special-K]

Originally Posted by bbcmudtruck

Big block freaks unite hahaha! I think I understand what your saying here and that is adding the extra stroke and CI will increase the torque, which is what turns your tires. Although you won't get big block torque, you will see a pretty good gain. You can build a fairly budget friendly stroker depending on the condition of your block and what you'll be able to reuse.

Yeah, you got what I meant. No big block for sure. Sorta like a mini big block? How about that? A step between. It makes the 350 more of truck motor. It makes a truck run like a car with a 350. I'm talking same 350 vs same 383. I had a stock SBC400 in a '72 K/20 4spd 4.10 truck with 35" tires and it drove with virtually no pedal. It never broke a sweat and it got 12.5 mpg.

[Fitz]

Originally Posted by bbcmudtruck

Big block freaks unite hahaha! I think I understand what your saying here and that is adding the extra stroke and CI will increase the torque, which is what turns your tires. Although you won't get big block torque, you will see a pretty good gain. You can build a fairly budget friendly stroker depending on the condition of your block and what you'll be able to reuse. Have you decided on a budget yet? Ultimately, your budget will determine your power output. If your just reaching for a 400hp/400tq motor, it can be done with a $5000 budget or less. Again, it will depend on how much you'll be able to reuse from your old motor and the condition your block is in. Machine work can really eat up a budget with a quickness.

Of course, if you have an opportunity to pick up a running and complete BBC, I'd go that route!

Good advice. I'll stay with my big block. Because, well, it's just BIGGER!

[Swar]

It all depends on what you want to do with the truck. If you are planning to take it to the track often and run the heck out of it, a 383 would be a good build.

If you want to drive it around daily and have something that surprises everyone on the road, you might as well just build the 350 to the max.

I don't have 383 experience, I'm sure it's a whole different animal, but I built my 350 up and I'm happy with it.
I'm running 10.2:1 compression, comp cam (biggest I could go for street) Edelbrock Aluminum Vortec heads and intake, and dual quads. I've left Harleys in the dust with it.

[turp mcspray]

A decent street engine, will make in the neighborhood of 1 hp/ft lb torque per cubic inch. So going from a 350 to a 383, you can expect a gain of 30ish hp/lbs of torque gain over the same 350. Some people have the impression that it will be a huge 454 like gain in tire shredding torque. A little gain is always better than no gain. If you are going to a complete rebuild anyway, I would go for more cubes. If your engine is good, add some vortec heads, and a modern cam grind, and you will most likely be very happy with those upgrades!

[Stocker]

Good discussion. All I can add is that when I had my 350 rebuilt many years ago, I considered a 383 but didn't want to spend the additional $500 I was quoted. My K20 is a bit on the heavy side, and carries the occasional load of firewood. I have always regretted not spending the extra money for more torque.

[Sklptrljay]

Thanks, for the thoughts. I am hoping to get my 3.08 to 3.73 swap done today (waiting on some parts). I'm hoping that removes some of the turd factor from my current power situation.

I am planning to put in a 700R4, which should help things a little more also.

I don't plan on doing wheel stands or 9 second quarter mile runs. I just want the feeling of being pushed back in your seat kind of fun I've had in other vehicles. And yes, one of those was a big block (66' Chevelle SS 396) and there is no comparison, but I can't justify the budget for that right now.

[mechanicalman]

Originally Posted by Sklptrljay

So in the next year or so I'm contemplating making the upgrade from a 350 (rv cam/ Holley/ Edelbrock intake) to a 383 with a similar setup and maybe some aluminum heads and Vortec setup. I bought the truck with the current drivetrain and it's ok, I guess. It runs pretty well, but it lacks oomph, if you know what I mean.

Has any one done this?

Is it noticeably better?

Does it in your opinion, justify the expense?

More justifiable if you still had the 3.08 gears, the 3.73 gears will of course help the 350 however a well tuned 383 with headers, 3.08 gears and T350 would have worked for you and then some, IMO.
3.73's, 700R4 with the 383 will be like having a granny gear in low, LOL.

The following info is applicable for 350 or 383.

What is your total timing and at what RPM does it come in? Is the carb calibrated well? Out of the box distributors and carburetors are hit and miss in regards to fine tuning.

Compression ratio is another thing, it helps to know what you have to match it with the cam you are running. Typical "RV" style cam is like .425" intake lift, .444" lift exhaust, 204 degrees intake duration @ .050 lift", 214 degrees exhaust duration @ .050" lift and like 112-114 LSA.

Do you know your cam specs and your compression ratio?

http://www.crankshaftcoalition.com/w..._compatibility

Do you have headers and dual 2 1/2" exhaust with cross-over? If any prospect of 383 in the future, do not let anyone talk you into duals smaller than 2 1/2".

For a 350 at least Ram's horn manifolds and at least 2 1/4" duals with cross-over.

[Sklptrljay]

Originally Posted by mechanicalman

More justifiable if you still had the 3.08 gears, the 3.73 gears will of course help the 350 however a well tuned 383 with headers, 3.08 gears and T350 would have worked for you and then some, IMO.
3.73's, 700R4 with the 383 will be like having a granny gear in low, LOL.

The following info is applicable for 350 or 383.

What is your total timing and at what RPM does it come in? Is the carb calibrated well? Out of the box distributors and carburetors are hit and miss in regards to fine tuning.

Compression ratio is another thing, it helps to know what you have to match it with the cam you are running. Typical "RV" style cam is like .425" intake lift, .444" lift exhaust, 204 degrees intake duration @ .050 lift", 214 degrees exhaust duration @ .050" lift and like 112-114 LSA.

Do you know your cam specs and your compression ratio?

http://www.crankshaftcoalition.com/w..._compatibility

Do you have headers and dual 2 1/2" exhaust with cross-over? If any prospect of 383 in the future, do not let anyone talk you into duals smaller than 2 1/2".

For a 350 at least Ram's horn manifolds and at least 2 1/4" duals with cross-over.

Unfortunately, I don't know any specs on my engine. It came with the truck. I do have 2 1/4" exhaust and headers, My mechanic helped me set the total timing and tuned the carb, so I'm getting all I can from the 350 right now.

I think with my situation as far as time vs money (I don't have enough of either) I would be better off buying a crate engine. I have been checking out some online and they are fairly reasonable, and well made.

I will read the info you linked, I appreciate it. You have a wealth of knowledge on this stuff, I always read your posts on these topics. When it comes time to pull the trigger I hope you don't mind if I pick your brain a little.

[Boog]

Jay you know the old saying "theres no substitute for cubic inches" ? More is better most every time. 😉 however those 3.73s will add some grunt to your 350 over the cruise friendly 3.08s. And they will work very well with the od.

[Sklptrljay]

Originally Posted by Boog

Jay you know the old saying "theres no substitute for cubic inches" ? More is better most every time. 😉 however those 3.73s will add some grunt to your 350 over the cruise friendly 3.08s. And they will work very well with the od.

Yeah, that was my hope. I have it all back together and just need to bleed my brakes before the first test drive. I went back to work today on night shifts so maybe in a couple of days I'll have an update.

[Boog]

Originally Posted by Sklptrljay

Yeah, that was my hope. I have it all back together and just need to bleed my brakes before the first test drive. I went back to work today on night shifts so maybe in a couple of days I'll have an update.

You know while you are replacing that rearend this is a prime time to add rear disc brakes, if you have a mind to. Just sayin.

[Lattimer]

A well set up 350 can be pretty stout. A well set up 383 has got to be more fun.

I was buying a crate and decided to go with the 350 based on cost. I couldn't make myself spend the extra at the time.

Depending on what heads and pistons are in your 350, there is a wide range of power in those engines. Early stock 350's were about 275 HP, that dropped to about 175 HP with all the smog crap in the 70's.

Mine is a 9.6:1 compression, cast iron vortec heads. It engine dyno'd at 382 HP/402 ft-lbs when it was built. I have a TREMEC 5 speed and 3:73 rear, and much more power wouldn't be useful in my truck. I can barely put this much to the ground. I can ease into 2nd gear, then pedal it and break loose easy. Ass end is just too light...LOL.

So depending on what you have, a 350 can be a slug or it can be awesome. A properly set up 383 is just going to be more awesome. How much awesome do you want, and how much do you want to pay for?


I will say this-----looking back now, I do wish I had spent the extra $1000 and gone 383. I would have had to buy other stuff as well, bigger carb, etc. But I do wish I would have.

[piecesparts]

I put a 383 into my 84 truck and with the right combination of heads and cam, the change is very noticeable. We did some things wrong with the first motor and at 20,000 miles I went back into a second time and did it again. Of course you learn as you go and we blew a hole in the engine block when the #3 rod broke. So build number three now has more goodies in it and with the block being bored .060 over vice the .030 over, the cubes are jsut slightly larger than a 383. I can cruise at 70 to 75 MPH with a 700 R4 tranny and get 15+ MPG, using a set of 3.73 gears and still if needed burn tires to no end. It will eat up a pony car with very little effort.

Just a point of contention that many will argue. Use quality parts to build, so you do not have to do it more than once. I now have more than I owuld have really wanted to invest in my 383, but it as close to heavy duty, bullet proof, nearly amybe indestructable as one could get it, until I start it. Forged Crank, H-beam rods, etc....

[enaberif]

I think with a 350 people forget that with a few dollars spent into them you can actually make them wake up very nice.

You put a healthy torque cam into it with a good set of headers a good aluminum dual plane intake and you can push over 450ft/lbs of torque out of them. And you would still be way under the cost of a 383.

Personally to me though if I am considering a 383 I would just go big block and call it a day.

[adricar1]

Big blocks have the benefit of more cubes,more torque but also the motors weigh more than a small block. Not a problem in our trucks , but in a light weight like an ultima then the weight will effect handling. It would be interesting to see how a big block motor and a stroker would handle around a road coarse in a prepped c10.It would be the mouse vs the rat

[leftybass209]

I always think about longevity. A mild BBC would ideally outlast a SBC stroker in reliability over the course of the motors life. That being said I don't think there's anything wrong with an SBC stroker and the difference between that and what you have now would be night and day. You need to decide your RPM range though, that can help you decide if it's worth it.

[oldertruckfan]

in the end , speed costs money. How fast ya wanna go?

[Heavymetl]

Hey, since we're spending his money, just go LS!

They're worth ~100hp over a comparable SBC cubic inch for cubic inch.

[Sklptrljay]

Originally Posted by Heavymetl

Hey, since we're spending his money, just go LS!

They're worth ~100hp over a comparable SBC cubic inch for cubic inch.

Lol! Yeah, please don't spend it all, I have a family to take care of!!