chevy sb 400

[pokethesmot]

hi this is my first post here but ive bean kinda lurking around for the past few days....i just got a 82 Chevy step side truck...and i was wonder what are some easy and less costly mods i can do to my engine to get a little more power out of it and like whats a good carb for it also thanks in advance for the advice.

[badblu97]

First of all, Welcome!! You will find a great bunch of people here, and a wealth of information! I too have a 400 SB, as far as cheap mods, headers are not too costly, exhaust isnt usually bad, I have a melltone muffler, great sound and performance next to flowmasters and the like. Carbs can get up there as can machine work and all. Look for electric fans, try synthetic fluids, every little bit helps! Mine is bored .30 over (406ci), roller rockers, block hugger headers (going on next) cam, intake, and carb matched from Edelbrock. havent had it dyno'd but I sure wish I could! Good luck! Save your pennies!!

[pokethesmot]

about how much hp does a stock 400 have and do you like the 400 like is it reliable and all that and thank ya

[MrBeast]

A word from the wise on the SB 400, do not tow with it. Expecially once the motor has been bored over. I had one that I had rebuilt from a very reputable shop, and they warned me not to tow with it.

I did anyways, and messed it up bad.

They are great motors otherwise, but they dont handle getting hot well.

[78 Chevyrado]

Welcome aboard!

Best bang for the buck upgrades are an intake and carb, and a new cam.

Try the summit website or catalog and look for summit brand stuff. You can get a double roller timing set for $29 a cam and lifters for $79 and an intake for around $80-100 for an edelbrock (prices are last time I checked on them). If you're near them I'd go check the store out, It's like a car parts candy store, most everything is on display. Every so often I drive the 70 miles to go wander for a few hours

Depending on what year, the later ones (they made them from 1970-1980) had 175hp, I'm not sure how much torque. emissions junk really bogged these down and the cams were way retarded so the first upgrade should be a cam, then a good intake and carb, then headers. Me personally I like a single exhaust system sound better so I'd get 2.5" pipes into one 3" pipe out to the back. or if you have headers with 3" collectors, 3 " all the way out. If you get duals I wouldn't get biggers than 2.5 pipes.

Good luck!

[pokethesmot]

Originally Posted by MrBeast

A word from the wise on the SB 400, do not tow with it. Expecially once the motor has been bored over. I had one that I had rebuilt from a very reputable shop, and they warned me not to tow with it.

I did anyways, and messed it up bad.

They are great motors otherwise, but they dont handle getting hot well.

i heard some thing about boring some steam holes if i dont have them where would they be at if i already have steam holes

[shrtbx]

I have a 400 in my 81 el camino bored .030 over as well. I did a lot of research on the engine before i snagged one. Edelbrock cam and manifold matched set up worked great for me. Its not the best choice for extreme off roading though, because they tend to over heat. Its stange because i think alot of the older 4x4 blazers came stock with it. The main thing you have to worry about with these blocks are the siamiese cylinders they tend to run hot because there is no space between cylinders for water to flow. Thats the reason for the steam holes. So if you plan on getting new heads make sure you have steam holes drilled or you are asking for trouble. Also If you plan on tryin to squeeze out more horsepower dont half step on the cooling system, especially with the 400.

[Dooley]

Never had any problems with my 400's. I have a 1971 30 over now in an old plow truck that has pushed, pulled, and towed for 20 years without problems. More info here.

http://www.67-72chevytrucks.com/vboa...d.php?t=297802

http://www.67-72chevytrucks.com/vboa....php?p=2972086

[PhilaTruck]

With my 406, I've hauled rock, brick, dirt, sand. No problems. And that's with a lumpy cam and 700r4. I also have a new stock radiator.

[mickman77]

had a 400 in my '77 k-20. pulled it, sold it, and dropped a 454 in it's place. from my research, a 400 is more headache than benefit but, that's just my opinion. and we all know what those are like...

[pokethesmot]

how hard would it be to put a new cam in and what would be all the benefits also would vorteck heads fit on it