350/290 Crate vs. stock 72 350 4bbl power?

[brown7373]

When replacing a stock 350 4bbl (72) is the 350/290 power about the same or is it more powerful. I'm not looking for a big upgrade, but a little more is not a bad thing. I just don't want to go backward. The way engine power has been rated varies depending on the year, accessories, rear wheel etc.

[dirish]

290hp has more hp. I believe 20-30. I believe 250 was originallythe factoryhp.
I have a 290 crate engine and love it! Mini starter gave me fits, but runs great!

[Coley]

Be careful with the 290hp crate engine..

I believe it has been built and intended for producing its hp up higher than what would typically be needed and used in the trucks.
So it typically is a better choice for lighter vehicles like Nova's, Camaro's, Chevelle's, etc, etc...vs the 4000lb + trucks.

I recall seeing that it is not recommended for heavier vehicles (ie: trucks) due to the fact it produces minimal torque down low...which is what trucks need.

As a result a few guys have seen their low end performance actually drop...given the fact that they don't often go above 4500-5000 rpm in their trucks.

First tho', you have to figure out where you do most of your driving rpm-wise and then where you want your power band.

The primary issue here for a lot of guys is they are constantly referencing the conversational 'hp' number.....and rarely the torque/rpm number, which is substantially more useful and more likely to be the driver of (heavier) truck performance.

....food for thought and maybe some of the other guys can weigh in on this.

Coley

[Steeveedee]

Yup. It's why my FiL bought the truck with the 402 in it- for grunt. But just going big block from small block costs a lot of money too, unless one has a donor.

[Mike C]

It's quite a bit more cam than cam in the truck motors. If I was swapping it into a vehicle that had 3.07 gears (or 3.73 for that matter) I'd also add a 2000 rpm converter to make up for that.

https://www.gmperformancemotor.com/parts/19355658.html

[palallin]

Why not keep the original??

[Coley]

Note that, in that link.... it is not intended for 'Marine Applications'.
I think part of the main reason for this is that it does not produce low end torque which most marine engines require.
I've seen guys swap out performance car engines into boats and their power dropped right off, at least where they want it (ie: 'out of the hole- go')...much to their surprise, again noting that boats (like trucks) need and want their power 'big' at the bottom end to get things moving.

...interesting to keep the feedback coming.

Is the truck in question a 3/4 ton? or a 1/2 ton?...noting the 3/4 ton is heavier again.

All good
Coley

[68Gold/white]

Originally Posted by Coley

Note that, in that link.... it is not intended for 'Marine Applications'.
I think part of the main reason for this is that it does not produce low end torque which most marine engines require.
I've seen guys swap out performance car engines into boats and their power dropped right off, at least where they want it (ie: 'out of the hole- go')...much to their surprise, again noting that boats (like trucks) need and want their power 'big' at the bottom end to get things moving.

...interesting to keep the feedback coming.

Is the truck in question a 3/4 ton? or a 1/2 ton?...noting the 3/4 ton is heavier again.

All good
Coley

And, what gear???

[72bowtiestepper]

IMO the 260 HP 350 crate engine is a better choice with it's milder cam .383"/.401" lift & 112degree lobe separation (It is also less expensive than the 290 HP version )

[brown7373]

Mine is a 1/2 ton long bed. I am not positive of the gear, but I think I checked it years ago and it is 3.73, but not sure. Also, I already own the 350/290 and it is installed but not yet started.

[Coley]

Ok, so you already have the motor so you are already committed.

If it was me, I would drive it for 3-6 months and then solve whether or not I was happy with the performance and if it felt 50-75hp stronger than my original motor, etc.

Now for me (and we are all different), I would want it mostly on take off and in the lower range...up to 50mph.
Now, if the 290hp simply didn't feel like it was putting out....I would then spec a new cam to put in it...and I wouldn't worry about the 'warranty issues'...and the odds of the engine failing are low if the swap is done well.
The cam I would pursue would focus more on lift and lobe separation than duration. So I would be happy for forgo the 'lumpity lump, long duration sound for the performance at lower speeds.

Regardless, drop it in...fire it up and take it for a drive and let us know what you think.

All good
Coley

[Mike C]

Originally Posted by Coley

Note that, in that link.... it is not intended for 'Marine Applications'.
I think part of the main reason for this is that it does not produce low end torque which most marine engines require.
I've seen guys swap out performance car engines into boats and their power dropped right off, at least where they want it (ie: 'out of the hole- go')...much to their surprise, again noting that boats (like trucks) need and want their power 'big' at the bottom end to get things moving.

Coley

Propeller boats (not jet boats) need a smooth, low idle speed in order to shift smoothly. They also need minimum overlap on the cam when they have a wet exhaust so reversion doesn't introduce water into the cylinder.

[Coach]

I have the crate 350/290 in my truck. I did exactly what was stated by others, about 6 months after install, replaced the cam with a Melling MTC-1 from Summit Racing. Huge difference on the low end torque, idles smooth, no issues.

[mikecaddy500]

Try a 96-2000 vortek truck replacement. Pretty inexpensive and plenty of torque!

[red211]

The 290 hp cam spec is the same lift/duration as the 350HP L79 327 cam in chevy II and vettes. Not sure of lsa since I didn't dig, just glanced. I had that cam in the 350 a buddy gave me that I slipped in the 63. Not a bad cam, sounded good at idle but not overly strong below 2500. That was with headers, intake and 600 holley. 4:10 gear short stepper is pretty light too.

[brown7373]

Now that sounds familiar. I had a 350/350 69 Vette. It was fast, but REALLY cam on after 2500 rpms. I will have to run it and see how it goes. I don't want to drive a dog, but then again I'm not interested in racing anyone. Proof will be in the driving. Thanks for the input.

[garyd1961]

Originally Posted by Mike C

It's quite a bit more cam than cam in the truck motors. If I was swapping it into a vehicle that had 3.07 gears (or 3.73 for that matter) I'd also add a 2000 rpm converter to make up for that.

https://www.gmperformancemotor.com/parts/19355658.html

You don't want too much stall with 307 gears in these heavy trucks. I tried that and it didn't work very well.

[Mike C]

Most likely a 350 inch motor can't hit the 2000 rpm mark with an 1800-2100 converter, but even if it does that's only 2-300 rpm over stock. But you are right that you want your cruising speed to be above the stall point of the converter.

[6T7 C10]

The 260 hp version would be better for a pickup. However a better option and surprisingly cheaper version at least per Summit would be the L31 long block. You gain much better vortec heads, compression, roller lifters, no need for zddp oil, better matched cam, and extra ponies. You would need a vortec specific intake manifold and an electric fuel pump. I maybe biased but I went this route in my 67 C10. There are also good 383 long blocks for similar monies. If the truck is original then rebuilding the engine that came in it should be a viable option.

Okay I just read you have the 290 already. That changes things a little. If it is not already installed and time/monies allow you may want to put in a better matched cam. Either way stay with quality small diameter long tube headers, 0-5000 rpm dual plane intake manifold, 500 cfm vacuum secondary carb, HEI distributor, ZDDP oil, and <2000 rpm converter to make a nice little combination for a truck on the street.

[txbill]

Originally Posted by 6T7 C10

The 260 hp version would be better for a pickup. However a better option and surprisingly cheaper version at least per Summit would be the L31 long block. You gain much better vortec heads, compression, roller lifters, no need for zddp oil, better matched cam, and extra ponies. You would need a vortec specific intake manifold and an electric fuel pump. I maybe biased but I went this route in my 67 C10. There are also good 383 long blocks for similar monies. If the truck is original then rebuilding the engine that came in it should be a viable option.

Okay I just read you have the 290 already. That changes things a little. If it is not already installed and time/monies allow you may want to put in a better matched cam. Either way stay with quality small diameter long tube headers, 0-5000 rpm dual plane intake manifold, 500 cfm vacuum secondary carb, HEI distributor, ZDDP oil, and <2000 rpm converter to make a nice little combination for a truck on the street.

Posted via Mobile Device

[txbill]

Originally Posted by txbill

Posted via Mobile Device

Posted via Mobile Device

[special-K]

As far as a baseline goes for comparison, the '72 350 truck engine is rated @175HP and runs them right on up the road. If going for more power you want to look at bottom end HP and overall TQ and ignore advertised top end HP.

[71c10longbed]

From what I have heard is that it has a lot of camshaft for the compression ration - still ~8.5:1 with dished pistons and 76cc heads. That makes the low end kind of weak.

The marine comment has more to do with the overlap of the camshaft and water reversion - i.e. sucking water into the engine. Most marine engines have water cooled exhaust and that limits camshaft choices.

[nevada]

my 72 C20 with original 350 / th350 is fine around town but had a reality check pulling a small 1500 lb trailer up the mountain, was constantly downshifting, lacking torque. my motor is tired, need an upgrade

[67 chevelle]

Originally Posted by mikecaddy500

Try a 96-2000 vortek truck replacement. Pretty inexpensive and plenty of torque!

defiantly , great engine , l31 is a perfect truck engine , way better quality than a "hencho" 290 , and though its rated less hp , you get more , and the torque , gas mileage , and power curve are way better