400 4 bolt main

[mopar346]

I have run across someone who claims they have a 400 SBC 4 bolt main. I thought they only made 2 bolt mains. Did they in fact make a 4 bolt that I am unaware of???

Thanks, Kevin

[acelr8]

Yes made in 70 and maybe 71.Usually has 3 freeze plugs down side also.Jeff

[mopar346]

Thanks, are they strong or beefier through out like a 350 4 bolt? What was there HP rating? Any specs?

[DeanZ10]

BTW
The 400 is externally balanced. Had one 30 years ago in a 69 with 4 speed. VERY torquey car.
Could take off in 3rd gear and smoke the tires. It was basically rebuilt stock.

[mopar346]

So do you think a 4 bolt main 400 is a better bert than a 4 bolt 350/383? It appears to be the same money either way. It is going in a 89 4X4 1500 auto. Should I step up the cam to something in the 460 - 480 lift range with the p[roper heads of course.

[dutch]

From what I have heard the 4 bolt version of 400 block isn't a strong as a 2 bolt one especially after a 2 bolt version has been converted to a 4 bolt configuration with splayed caps and bolts - but unless you're racing it it wouldn't make any difference I suspect.
Given the choice (especially for a truck) I would choose the 400 motor properly cammed over a similar but smaller 383 type - no replacement for displacement...
They both have loads of torque done up right but the 400 probably more - and as long as you make sure it is cooled right it should win the torque war and move that truck pretty well!

Randy

[mopar346]

Thanks.