400 Avanti!

[mfg]

A 400 CI Chevy engine will replace the 350CI Chevy engine in a '69 Avanti ll with no issues....other than the usual stubborn fasteners.....True?

[Avanti83]

Yes, everything bolts to either one. Nate put a 350 in my 74 for the OP replacing the 400.

[plwindish]

Yes, a SBC is an SBC, so things will all bolt on with no problem.

[mfg]

Actually, the answer here is FALSE!..........Before the 400 can be bolted into an Avanti ll which originally came with a 350, the special externally balanced flywheel (400CI only) must be sourced.

[Avanti83]

And a Harmonic Balancer change is also required by your definition of an engine change. You can't use the 350 heads on the 400 either, but those parts we are discussing are part of the engine and IMHO when you swap the "engine" those are parts that come with the engine. If the question was short block then I'll agree with you but that was not the question.

When Nate Altman changed the 400 to a 350 in my 74, one engine came out and another went in. No exchange of parts just what came with each engine. The T10 was removed from the one and bolted to the other so we'll need to agree to disagree on the correct answer to this one.

[warren55]

I agree, the question is misleading unless you specify that we're staring with a short block. The carburetor might need to be re-jetted too, if it was taken off the 350.

[mfg]

All good points!....but a 'complete long block engine' ends at the crankshaft rear face...(IMHO) thus, the 400CI flywheel would be needed. The 350CI flywheel will not function properly on the bigger engine!

The question, as stated, is still.....FALSE!

[mfg]

I'd like to add another comment...........Replacement engines, from what I've experienced over the years, generally come out of the factory crate WITH their respective harmonic balancer....but, once again, END at the crankshaft rear face...Why?.....because most all engines are compatible with either a standard or an automatic transmission...This, of course, means that particular engine may require a stick shift flywheel OR a torque converter flex plate.........and the factory/rebuilder AIN'T GOING TO SEND BOTH!!!!!

This hypothetical repair shop would need to scare up a '400 only' flywheel OR flexplate before that big baby could be installed!!!!

[plwindish]

I found out when the trans shop that swapped in a 200R4 for the Turbo-hydramatic 400 on my 76 with a 400 motor that another flywheel and torque convertor had to be used in the swap as well.

[PackardV8]

All good points!....but a 'complete long block engine' ends at the crankshaft rear face...(IMHO) thus, the 400CI flywheel would be needed. The 350CI flywheel will not function properly on the bigger engine!

The question, as stated, is still.....FALSE!

I'd argue TRUE. A "400" Chevy engine" is ready to bolt up to a transmission and needs only fluids to be ready to run.

The original question didn't state "long block" but in any case it is mis-defined above. There no such thing as a "complete long block engine". It's either a complete engine or a long block. As defined by the American Engine Rebuilder's Association, a long block includes short block, heads, valve train, but not the flexplate/flywheel/front damper, manifolds, sheetmetal or accessories to make it a complete engine.

jack vines

[mfg]

All good points!....but a 'complete long block engine' ends at the crankshaft rear face...(IMHO) thus, the 400CI flywheel would be needed. The 350CI flywheel will not function properly on the bigger engine!

The question, as stated, is still.....FALSE!

I'd argue TRUE. A "400" Chevy engine" is ready to bolt up to a transmission and needs only fluids to be ready to run.

The original question didn't state "long block" but in any case it is mis-defined above. There no such thing as a "complete long block engine". It's either a complete engine or a long block. As defined by the American Engine Rebuilder's Association, a long block includes short block, heads, valve train, but not the flexplate/flywheel/front damper, manifolds, sheetmetal or accessories to make it a complete engine.

jack vines

I'd say you haven't had all that much experience installing engines Jack, ...that is if you really think they are shipped with flywheels or flexplates. Also, when someone writes "400CI Chevy engine",....I'd figure they were speaking about a complete engine....but that's just me!!!

[PackardV8]

I'd say you haven't had all that much experience installing engines Jack,

Only been doing it for fifty-five years and I do sign my name to any statements I make.

jack vines

[mfg]

Only been doing it for fifty-five years and I do sign my name to any statements I make.

jack vines

MORE POWER TO YOU JACK!!!

[Devildog]

Just to stir the pot a bit more, a 400 SBC can be balanced internally (usually externally). I have two of them in my other cars with two different fly wheels and tranny set-ups.

Love the trivia questions ! Thanks for doing them.

Joe

[mfg]

Just to stir the pot a bit more, a 400 SBC can be balanced internally (usually externally). I have two of them in my other cars with two different fly wheels and tranny set-ups.

Love the trivia questions ! Thanks for doing them.

Joe

Thanks a lot Joe!....I realize that some of these questions are a bit 'lame', but gosh, sometimes my brain starts to hurt trying to think more up!!......Take care, Ed (mfg)