what compression ratio should i get for my rebuild kit for the 350 that im getting? whats best? on 93 octane

 

For maximum performance on 93 octane gas on a carbed street 350 with cast iron heads I would build for a finished cr of 10.0:1.
Alumium heads will tolerate about .5 cr more.

 

thanks!

 

i've always heard 9.5 for iron and 10.5 for aluminum.

 

i think im just gonna go 10.0:1

im hoping for 400 hp outta this engine at one point

can someone explain camshafts to me? and whats best to get?

 

not to be a jerk but if you need us to explain camshafts then i'm gonna assume your decision to run 10.0:1 isn't based on much besides F'Birds88's suggestion. i'm not saying anyone's right or wrong here, just that you need to do some more research because having too much compression will create preignition which will destroy your engine very fast. i would wait for an answer from someone that's actually running 10:1 on pump gas and iron heads. even then other factors will play into how much cr you can have, like the cam you choose and ignition timing (advancing timing increases temperatures and the risk of preignition).

 

If you check my info in the readers ride section of this
site you'll see that I do run 10:1 cr. My car does not quite make 400 crank hp but is real close. (about 375/380 gross{based on 1/4mi mph not dd2000}). A simple camshaft change would put it well into this zone. If you would like a formula to build by
that *works* and will get you there the *first time* for the least amount of cash spent, then copy mine and select a cam a little larger. Like a Comp cams XE274H.
This would get you over 400 hp and over 400 ft/lbs torque
and run a strong 12 sec quarter mile et. Yet will be quite manageable on the street. With a cool street machine sound at idle. Althou there are many, many ways to skin a cat, this formula is one of the most economical ways to go to reach your performance goals.
Pick up some books on building up a Chev small block engine.
Like David Vizards "How to build a Chev Small Block on a Budget"
Among others.
Lots of info on Camshafts and selecting them.
There is also lots of info availabe on various Camshaft companies'
web sites, online. The camshaft companies all have online and phone'tech lines to help you get the right valvetrain parts for maximum performance.

https://www.thirdgen.org/rides/index...ew&rideid=7360

 

well, i am gonna get aluminum heads...but i dont wanna go as high as 10.5...i was gonna stay safe at 10...and im building the engine from the block up, so i have not gotten a cam yet, and a cam wont come till round christmas time, so i wanna know whats best for my application

thank you for the sigguestion on those books, im gonna go to the library today and look for some.
here is a list of some things i have been thinking about:
Rockers (what ratio do i need?)
cam (i want a lumpy SOB)
alum. heads (whats best to buy? trick flow? edelbrock?)
comp. ratio/pistons/rebuild kit(i need the ratio, also. forged or what?)
intake manifold(edelbrock? or a polished one from summit? what kind of edelbrock?)
carb(what CFM? will i get more out of a 4 barrel or is two ok?)
trans(t400 or th-350?)
rear (i have a 2.77(i think) posi, will it hold up?)
anything else i can add to the list?

 

comp and lunati among others have very good info about cams and what all the numbers mean in their catalogs. it'll help you better understand what everything means and how it relates.

 

I think I see a potential problem with your setup.You really shouldn`t run a huge cam with an auto and 2.77 gears.You
won`t have enough bottom end torque to pull you out of the hole, and you will cross the line with your rpms too low.You
should have at least 3.73 gears especially with a 3 speed auto
because they don`t have as low a first gear.

 

i have a 4 speed auto, and i want to get 3.73 gears....here is something else
i have a 2.77 posi, could i take the posi out and put it in an open 3.73?

 

I could be wrong, but I don't think you have the right carrier to get 3:73 gears.