71 Roadrunner engine choice viper 8.3 or Hemi 392

[71RRGtX]

Hey guys,

Im currently in the process of building a 71 Roadrunner. I have the RMS front and rear kits and now need to decide on the engine.

The 2 options i have is, Viper engine, my builder already has this available with the 6 speed transmission, modified wiring harness and unlocked PCM. (10k cost) and is ready to go.

The other option is to go for Hemi 392 setup which would probably come in at more more money but has other advantages.

Any thoughts/comments most welcome.

Thank you

 

[1967coronet440]

That viper set up would be wicked, if I had the option that’s the route I’d go. Depending on mileage, what’s it got on it??

 

[biomedtechguy]

Viper setup is going to get more attention, by FAR.

 

[Dennis H]

V10’s sound like UPS trucks (to me). 392 w/Blower.

 

[Photon440]

Depends on the engine, Vipers had from 400 to 645 hp., which engine does your mechanic have? The 392 will fit with far less hassle because of the shorter length.

 

[71RRGtX]

Its a Gen3 viper engine and transmission. Circa 500hp

 

[71RRGtX]

Here it is test fitted in the RR

 

[Ugk]

392 gets my vote

 

[biomedtechguy]

Its a Gen3 viper engine and transmission. Circa 500hp

 

[Budnicks]

Viper V-10 will get more attention

they do have a different exhaust note

but a well adorned 6.4/392, 6.1, or a hellcat or 426 (still gen 3)
lots of variations of the newer hemi's
will not be a slouch either