350 tbi to 406 tbi

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Supercharged111

Truly Awesome
Joined
Aug 20, 2015
Messages
12,615
Reaction score
15,241
I knew the bores were iffy, but it seems like I've been seeing a good bit of 406 builds mentioned lately.
 

b454rat

I'm Awesome
Joined
Jul 25, 2019
Messages
1,705
Reaction score
1,413
Location
Windsor NY
I love 400s. If I had the money Id build one for my Yukon. I have a block ready to go, just need everything else lol. Ive built a couple, and one that built with TBI stuff, and was an absolute torque monster. Can't imagine one with Vortecs n a roller cam....
 

df2x4

4L60E Destroyer
Staff member
Super Moderator
Joined
Mar 1, 2012
Messages
11,157
Reaction score
12,682
Location
Missouri
So 350 heads fit just by drilling a few holes? I was under the impression you were stuck with the smog heads.

That is correct.

Seconding (or thirding?) this. When my dad and I had the 400 in his Monte Carlo rebuilt we used some Edelbrock small block heads and had the machine shop drill the steam ports in those. A few years later and no issues.
 

L31MaxExpress

I'm Awesome
Joined
Apr 21, 2018
Messages
5,890
Reaction score
7,540
Location
DFW, TX
I love 400s. If I had the money Id build one for my Yukon. I have a block ready to go, just need everything else lol. Ive built a couple, and one that built with TBI stuff, and was an absolute torque monster. Can't imagine one with Vortecs n a roller cam....

My 11:1 383 is torquey as hell. Could not imagine a 396 stroker or 406 in the same setup. Someone did some software modeling using something a little $$$ and better than Destop Dyno for me after swapping cams. Sky blue/red lines represent the current cam/rocker combination. My low-end under 3,500-4,000 rpm is a bit better because of the Rhoads lifters as well.

A 3.875 stroked 350 (396 cubes) or 3.875" stroked 400 (420 cubes?) would pull like an absolute freight train built the same way.

You must be registered for see images attach
 
Last edited:
Top