me and a buddy are putting together an 85 Cutlass with a 406.
my question is would you go with the 406 or would you destroke it and go with a 377.

i need details

 

Where do you want your power? lower in the rpm band or higher, destroking makes for high winding engines that require QUALITY parts for longjevity. Not real useful for a street car, race car yes.

 

A 406 will put out more peak HP and TQ. Are you willing to sacrifice low RPM torque for higher RPM HP above 6500?; because that's the only place the 377 is gonna make more power than a 406, all else being equal.

I know. Why don't you just pull it and put in a 350? That's a much easier and less expensive way to get less displacement and less power?

AJ

 

Destroking will cost more, and you'll get less.

Stick with the 406. Dont try to make things more difficult.

 

do a 406

 

...

 

well i surely don't want to make things more difficult
what kind of RMP range does a 406 have?
here's what i thinking about doing
406
5.56 rods
400 crank
flattop pistons
500ish lift 270-280 duration cam
1.6 RR's
a set of recondictioned heads
2.02-1.60 valves
160cc runners(i know that'll be a restriction down the road)
single plane intake
700-750 cfm carb

our goal is to get it running into the high 13's low 12's.

 

if your going to use the 5.56 you should upgrade to the 5.7 rods it wont cost more than the rods, except you need to get the pistons with a higher pin height. You should also balance the assembly too

 

I know someone that would spray 200shot with a stock bottom end and still twist it 6500. I don't agree with the logic,, but its doable.

Select a good piston/rod combination and use a good cooling system. You will never have to mess with it again.

 

do the 406, unless you are wanting to do a little round track racing.

 

mine can go to 6400.. but if it seeing even 6000 its a miracle.. i usually done go past 5800-5900