Has anyone ever built a 377 smallblock and how did it run.

[upacreek]

I have a 400 block and I have a forged crank for a 350 and hbeam rods
all I would have to do is buy pistons and bearing spacers. Has anyone built this combo and how did it run. I know a lot ov people go the other way and build 383 but i dont hear much on this build. Anyone who has built one or knows anything about them pleas let me know.
Thanks

[dennis68]

377 is a much better engine IMO. You get the added benefits of the big bore and improved breathing from unshroudng the valves while maintaing the short stroke for revinn' the snot out of it. :3gears:

[jcs]

That is what I have in my 1968. It is pretty mild (297hp at the wheels), but it runs very well, and I'm happy with it. It could be me, but it feels 'punchier' than stroker motors I've been around, even with a heavy flywheel. I agree with the previous post that you can rev the snot out of them with the right parts (which I don't have!).

[dennis68]

A 377 should have a lighter flywheel. 383 and other stroker combinations use externally weighted flywheels while the 350 crank variants use the lighter internal balance flywheel.

[jcs]

I agree with the above, good point - I just meant a heavy, OEM style flywheel as opposed to an aftemarket lighter one, aluminum or something racier to really make a quick revving motor. The 377 uses 350 balance stuff.

[carbuff]

I built a pretty stout 377 for my 2nd gen Camaro and I absolutely loved it!!! It was a no-holds barred type motor (cost me a fortune), but I regularly spun it to 7000+ rpm with no problems. The solid roller cam and big heads meant lots of trips to the 7500-pill MSD rev limiter! :)

The setup made 460-ish rear wheel HP and about 375-380 ft-lb of rear wheel torgue. I gears the car low (4.56 rear end with a T56), so I could keep it in the upper RPM as much as I wanted. :)

I highly recommend a 377 if you enjoy spinning a motor and are willing to give it the gear to use the rpms...

[CoryM]

377ci is my favorite sbc. You can build them for high rpms while still having enough torque to move the car around at lower rpm. A great street/track engine because you have enough torque that you don't have to be perfect with your shifts but can still rev it up at the end of the straight (if you have the valvetrain). You generally get almost equal hp/torque. With all de-stroked engines you do lose a little of the bottom end torque, but if its in a car under 3500lbs you wont miss it at all.
The first sbc 377 was actually a bored 327ci stroked with an AMC crank. They were in the GS vettes and the cheetahs. Of course the more common 377ci is a destroked 400 with .030 overbore. I have a 377ci as well, but its an oddball. Its a 350 block, .030 over with a custom crank from a 360ci sprint car. He was cheating by a few ci and got caught so I got the crower ultralight crank/rods :D . Definitely a fan of low rotating mass now after having an engine with a very light bottom end.

[chicane67]

377's rock, period.

In a 3000 to 3400 lb chassis, a 377 will be a blast. When I was working for some old guy in the business, we put TRACO 377's in the finished product....... and let me tell you about smooth, rock solid power curves that had high RPM hp that pulled that peticular 3200 lb chassis to over 180 MPH, got 26 mpg and passed California smog.

Did I forget to mention, it was a $14,000 engine package !?!!

Anyway, 377's are a great engine for lighter chassis'. Even if you went real budget, you could still make 400RWHP and not brake the bank doing it. The peticular package of a 4.155" bore and a short 3.5" stroke, with a long rod of-course, makes brutal mid range power and torque, with one impressive top end charge. Which is just what the doctor ordered, when you have a handling chassis, vice a stright line oriented chassis. You will scrub just a little low speed torque, but you will more than make up for it in the mid range power and torque, thats for sure. This make's for a more driveable and street mannered car..... honestly, life is really boring when you do nothing but spin the skins because you make too much low speed torque in a chassis that isnt sprung for it.

Great for smoky burnouts, but it does su*k when it swaps ends in a turn from wheel spin. If you have the means, I would build a 377. At least once in your life. You wont be let down by any means if its screwed together correctly. In the right chassis, it will fly, but the combination depends on what chassis you are running.

A 377 would be great in a Camaro/Firebird/Nova.

A 383 would be great in a 64-66 Malibu/GTO.

[ProdigyCustoms]

I like a 377 in a light car. The big bore unshrouds the valve nice, and the short stroke gives it the revs. The small bore / long stroke 383 is good for torque, but if i want torque I will build a Buick!
Of coarse there is no substitute for cubic inches, and if for any reason you need to buy a crank, I would build a 406 in a heartbeat over any of the other choices with this block. Built adentical, or even specifically slightly different to take care of one anothers advantages, the 406 cubes will outperform the 377 in anything over 2800 LBS, which your car will never be close.
Not long ago we took a 377 street racer, tore it down, changed the rotating assembly to a 406 and picked up a 3/10ths. It was a 2900 LB car.

[Neil B]

I'm building one now. Mine will be a 4.125" bore x 3.480" stroke 372ci. I'm using a Bow-Tie block with 350 mains (no spacer bearings required), 13.5:1 compression, [email protected] solid roller, and 218cc heads flowing 300cfm+. The only custom part I'm using is the cam, the rest is off the shelf.

Not too many people are building them because it doesn't cost any more to build a 406. But I've always wanted a de-stroked, high compression, big-cammed screamer - so that's what I'm building. It'll be a few months before it's done, but mine will end up in a 1st Gen Camaro street car with a Tremec 5-speed.

[rumblee]

i have always liked the idea of a 377, but why not just build a 406 and make more torque, and the same hp at lower rpms?

[Fuelie Fan]

I suggest you read the Hot Rod article this month on bore/stroke combos, some interesting info...

[Steve Chryssos]

I stood at the cross-roads: 377 one way 406 the other. Screamer one way Torque monster the other. When it was time to take the wallet out, I went 406.

..And I spin that poor little 406 to 7K anyway!!

You can tune the 406's torque curve higher in the rpm band with the right heads, intake, cam valve size and header to compensate for wheelspin. In the end, if you are building a street engine, a 406 just makes good sense. Spend the money and she'll rev to 7K like a freight train without giving up anything down low.

[graycamaro]

I work in a automotive machine shop and in my opinion for a street car there is no reason to destroke an engine. You can build a 400 or bigger engine for the same money and have more power in a rpm band that your actually going to use alot. Not to mention if built properly the bigger motor should have no problem spinnig the same rpm as the 377.

I am not sayin the 377 is a bad motor or a bad choice. We do alot of them for dirt track guys because they cut down on low end torque so they spin the tires less off the corner.