350 versus 400

[jacob_coulter]

My friend was going to replace his blown 350 motor on his 78 k5 blazer, and the local engine shop charges about the same price for either a 350 or 400 rebuilt long block. His Blazer originally came equipped with a 400, so this will be the 3rd engine.

All things being equal, is there any downside to going with the 400 over the 350? I've heard the 400 is better for low torque, and the obvious cubic inch advantage.

I'd appreciate any input.

Thanks again

 

[Avery4jc]

No replacement for displacement.

-Avery

 

[rjfguitar]

zi made the switch from a 350 to a 406. The low end torque is much better on the 400. The 400 is a mean motor for a small block, but it's a beast to keep cool.

I'd say that is why a 350 was used to replace the original 400, probably heat issues.

 

[tiger9297]

I'm planning a 383 now w/ Vortec heads and the Howell MPFI. I thought about putting that same top end on a 406 but all the drilling steam holes in the heads, heat issues, blah blah............I'm sticking w/ the 350 block. I figure the 23 cubes I'm missing w/ a 383 vs. 406 is not worth the simplicity and reliability I'll have by going w/ the 383. Just my .02.

 

[4X4HIGH]

400's are nortorious for over heating issues. Build a 383 instead, they have plenty of low end torque and aren't prone to the overheating issues associated with the 400. 400 blocks usually crack in the lifter valley also way more than a 350 block ever does. This is because of the simeased cylinder walls and the lack of cooling.