350, or 400 small block?

[Ace Champion]

Hello all, couldn't really find any info on this topic anywhere. I'm about to rebuild/build a mild small block for my truck. The truck has a factory 5.7 tbi/4L60E and it's a 93 C1500. I won't be reusing the tbi, I'm going to use aftermarket efi so that is a non issue. Just trying to see which I should get, I can get a 350, or a 400 for the same price. Would the "issues" with the 400 be worth the hassle for the extra cubic inches?

 

[Rock Hard Concrete]

Do a 383 its gonna be your best best and a good compromise for torque. If you really want the extra umph then you can do the 400 I wouldn't do it due to possible reliability issues especially if its tuned for more hp than stock.

If you're running an aftermarket efi then theres really no reason not to just stroke out your stock motor the parts arent that much more.

 

[Ace Champion]

Do a 383 its gonna be your best best and a good compromise for torque. If you really want the extra umph then you can do the 400 I wouldn't do it due to possible reliability issues especially if its tuned for more hp than stock.

If you're running an aftermarket efi then theres really no reason not to just stroke out your stock motor the parts arent that much more.

Thanks for the reply, I also thought about the 383 option. Just didn't know if I wanted to spend money on a rotating assembly. Was wanting to get a good set of heads, roller cam, etc....really just wanting something fun to drive with 400-425ish horsepower, that would be reliable enough to drive everyday if I wanted to without swapping a 5.3. Not worried much about torque cause I know it'll be there either way I go to an extent. Are the 2 piece rear mains on the 400 more prone to leak oil than a 1 piece on a 350/5.7? I know about the cooling issues, and the thin cylinder walls. Any other down sides to the 400?

 

[c1500deathtrap]

If you pay attention to your cooling system and use the right heads on the 400 you'll be fine. Same thing with the 2 piece RMS, some attention to detail in the build up goes a long way. A lot of your leaking 2 piece seals are from hasty factory assembly.

 

[Ace Champion]

If you pay attention to your cooling system and use the right heads on the 400 you'll be fine. Same thing with the 2 piece RMS, some attention to detail in the build up goes a long way. A lot of your leaking 2 piece seals are from hasty factory assembly.

I know whatever heads I could use on the 400 would need to have the steam holes drilled, at least that's what I have gathered anyway. And, for the cooling system. Would a big block radiator and e-fan combo be good enough? What do you mean when you say attention to detail regarding the 2 piece RMS? Thanks for your reply by the way, kinda learning this Chevy stuff as I go.

 

[c1500deathtrap]

-Why yes that will certainly cool it. A good aluminum 3 or 4 core will work as well.
-When you install the RMS clock the gaps so the main cap gap and seal gaps don't line up.
besides if you go putting a hopped up 383 in there you may find a cooling upgrade is necessary anyway.

 

[Supercharged111]

Wait, so all you have to do to run decent heads on a 400 os drill some holes?

 

[Terrick down Under]

Love this thread.
I am going to try the 400 path because i have one already.
Mine is a 97 (ex 6.5TD), that i will be running pump gas and propane, just because of where I live.
What would a stock inlet manifold etc cost me to connect to the factory harness and computer that I have already sourced from Jimmy.
BTW, sorry to highjack your thread.

 

[wheelman]

Hello all, couldn't really find any info on this topic anywhere. I'm about to rebuild/build a mild small block for my truck. The truck has a factory 5.7 tbi/4L60E and it's a 93 C1500. I won't be reusing the tbi, I'm going to use aftermarket efi so that is a non issue. Just trying to see which I should get, I can get a 350, or a 400 for the same price. Would the "issues" with the 400 be worth the hassle for the extra cubic inches?

 

[wheelman]

Do not use a 400 block for nothing
They blow out top of cylinders.in the middle.cylinder to cylinder.

Want stand up.to heat or power.use a 350 block or 454.turn a 350 in to a 383 or what ever.