What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

350 .40 over

C

Coyotehunter23

Registered Member
Joined
Dec 2, 2015
Posts
7
Reaction score
1
Recently pulled the motor out of my hunting truck looking for help. Been bored .40 over amd have it tore down at the moment. Have a weiand 8000 intake and a holley 650 i planned on putting on it. The cam is stamped 115850 on top and 241972 on bottom. Looking for any help i cangrt on improvements for power. Dont want to soend a whole lot but want some gain. I dont know much about putting an engine together any help is appreciated. The truck also has 308 gears if that matters. Thanks.
 
This might be better over in the garage, what do I know though? :)

I assume this is a 350? What transmission are you dealing with? Tire size?

3.08's are pretty pathetic gears in these trucks, if you have 31" or taller tires, they are going to start to be a pretty big hindrance to felt power. I think even for a hunting rig knowing the trans would help pick some other parts.

You won't find many here that will talk bad about the Quadrajet. It's not the best at anything, but it's most likely the best at everything. At least that isn't going to cost you $1000 and isn't called fuel injection. :)

Don't know much about that intake, but unless its some performer-type intake, probably more than the motor will use with those gears, unless you get the RPM's way up there. Even then, the gears are going to be a major problem. There's a reason that GM went with 3.73's and better when they could.
 
350 turbo trans 235/75/15 tires. So id be better off to find different gears than i would be to do any engine work?
 
just go with 26" tires!

Really though what heads you running? Getting the engine breathing is the biggest improvement. Good heads/cam/intake/exhaust.
Get your head numbers and post them up if you can.
 
If you don't want to spend a bunch of money, I'd think a mild cam and new axles (cheaper than re-gearing what you have almost certainly) would give you a noticeable bump in power.

My old 305/3.08 truck would go pretty decent, but I had to really hold it in gear for a long time to get it up to speed quickly.

I don't know if you'd want to live with 3.73's and that tire size though, others who run that combo might comment. I'm sure on the freeway ,with no OD, the motor would be turning something on the order of 25-3000RPM.

Is it mainly low speed that you use it? Just occasional freeway to get to/from hunting? Lower gears (3.73) are a lot nicer IMO when you are traveling at lower vehicle speeds.

Forgot headers too....they are a pretty consistent 25HP with long tubes on a "stock" small block, pretty hard to beat those gains for what you can get headers for.
 
Yea the pickup only is on pavement in town its not exactly highway worthy. Thanks i appreciate the help
 
Heck if its not a highway truck at all, and never will be, I'd say gear that thing way better. 3.73's IMO are about ideal, especially with that small a tire. Would still be decent with something as large as a 33" tire if you ever decided to go bigger.
 
You 83 is running tbi heads with carbed intake. I rebuilt the motor in high school when I had a 89 chevy with Tbi injection. Did some measuring and didn't seen any need to bore the cylinders. Did a quick hone installed new pistons and rings along with cam and crank bearings. Only upgrade I did was a compu cams computer cam designed to work with the conputer.

I'm sure the cam made minimal gains but the truck got 12 miles to go and felt healthy after the rebuild.

That was in 2000 I soon totaled that truck after putting a hp ford d44 in the front. I yanked the motor and axles and they found a home in a 83 k5 I picked up.

I didn't want to mess with a computer so I grabbed a carbed intake and carb off a 80s chevy truck. Yes it was a little redneck but it works.

The k5 I wheeled like crazy the small 525 or 500cfm carved is peppy and makes good power and the dang thing never stalls out I've tipped it on its side quite a few times and she runs till I shut her down.

What I'm getting at is big carbs are for big motors. A 350 40 over with a mild cambell isn't big. 650cfm might actually make less power and be dieing all over the place.

I think I'd run as close to stock cfm as possible on mild motor
 
Thanks for the help i have a quadrajet also but dont know how good of shape its in
 
Coyotehunter23 said:
Thanks for the help i have a quadrajet also but dont know how good of shape its in
Click to expand...

Rebuild kits used to be pretty cheap (~$20) no idea what they run now. You'd want to look at the innards before you committed to a rebuild, and you'd also want to check that (particularly) the primary throttle shaft closest to the throttle cable is not very sloppy. That can be bushed, but it's normally something you take somewhere to have done. I have no idea what ethanol does to the later "plastic" floats GM used, thats one of the things I'd want to look at. I've not heard anyone say their floats melted, by now I would expect it to be a common posting if it happened.

GM apparently completely "overcarbed" millions of cars and trucks produced from 1965-1990 on motors as small as 230CID with 750CFM, up to 800CFM on 305/307 engines.
I'm not making anything up, you can go look at David Vizards testing where he made more power with a 1000CFM carb on a 350, and said that it could be completely street able. Old wisdom about carb size is just that. Old.
 
Like dyeager said, gears.

As for the heads, the 487 casting heads are better than the 882, given that both are in the same mechanical condition. The heads may need freshened if it was an old rebuild.

Simple dual plane intake with a proper working Q jet and a mild cam with specs close to the Edelbrock Performer cam will work very well in your application
 
I've been researching what carbs are to big. See anything g from 470-650cfm for offroad motors. 750 if dual plain intakes are used.


Here's my small carb. She doesn't make mare much power. But man she never dies and just goes.

 
I had my local machine shop find out what cam i had. Was told its a mild cam so im going to use that. The have that weiand intake or the stock one and then like i said the holley or Qjet for a carb. Im workin on a set of axles at the moment also
 
You must log in or register to reply here.

Latest Posts

Top Bottom