350 performance upgrades - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum

Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
lost password?   |   register now

LinkBack Thread Tools
  #1 (permalink)  
Old 02-28-2007, 02:15 PM
Registered User
Join Date: Feb 2007
Location: alaska
Posts: 1
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
350 performance upgrades

I installed a new sb350 in my 85 chev pu a few years ago, upgrading from a 305. When I did the swap I kept everything stock to comply wih local IM but now I am not using as a everyday driver and I want to wake it up! I was wondering if anyone had any advice on carbs, intake, and exhaust systems. I am not looking for a race truck but I would like to have good clean relibile power, I have had this truck for 15 years and it has allways been way under powered! Any advice would be great.

Reply With Quote Quick reply to this message
Sponsored Links
  #2 (permalink)  
Old 02-28-2007, 06:52 PM
Registered User
Last photo:
Join Date: Jan 2006
Location: cornelius
Posts: 736
Wiki Edits: 0

Thanks: 49
Thanked 14 Times in 14 Posts
Heads are really where you make your power, what is the casting number? For a mild street engine you cant go wrong with a set of vortec heads you will need a vortec intake and valve covers. If you don't want to change the cam and heads you might look into 1.6 rocker arms.

An edelbrock preformer intake manifold. I think their still the best for a mild street engine. Holley or Edelbrock / Carter 600 or smaller carb. I like the Edelbrock, their easy to set up and hold the tune well. Long tube headers, with 2 1/4" dual exhaust, and free flowing mufflers, theirs a bunch to choose from.

An RV cam or one of the more modern cams, like the Voodoo cams. If you do use stock vortec heads don't use a big cam or high lift rocker arms. Stock vortec heads should be able to accept cams up to .420-.430 some people say more.


Last edited by xxllmm4; 02-28-2007 at 08:48 PM.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 02-28-2007, 10:34 PM
techinspector1's Avatar
Last wiki edit: DynoSim combinations Last photo:
Join Date: Oct 2005
Location: Zephyrhills, Florida, USA
Age: 75
Posts: 15,338
Wiki Edits: 326

Thanks: 1,504
Thanked 2,021 Times in 1,561 Posts
Or buy the bare heads and assemble 'em yourself with the Crane Cams high-lift kit, part number 10309-1. Includes retainers and springs, no machining for 0.550" valve lift with stock seals. In addition to the specific intake manifold, you'll have to run Vortec-specific rail rockers to maintain rocker/stem alignment. It sounds like a lot of trouble, but the heads are worth it in my opinion.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 03-01-2007, 07:39 AM
Frisco's Avatar
Glad To Be Here
Last photo:
Join Date: Nov 2002
Location: Canton, North Carolina
Age: 75
Posts: 2,245
Wiki Edits: 0

Thanks: 0
Thanked 9 Times in 9 Posts
Originally Posted by mcbride
I have had this truck for 15 years and it has allways been way under powered! Any advice would be great.
The cheapest way to get real "seat of the pants" improvement would be to change the rear end ratio to a lower (higher numerical) ratio. Look for around 3.70-1 up to 4.11-1 for street use. Fuel consumption will go up.

Another cheap (almost FREE) improvement is a good tune up and increasing the timing from the factory settings. Look for 10-12 degrees initial and 32-34 degrees Total mechanical for the STOCK engine. Use Full manifold vacuum source for the vacuum advance.

A good set of headers would be my next choice.

Next I'd consider a mild cam upgrade (not too expensive) followed by a better set of heads (getting up there in costs).

I'd skip the Edelbrock Performer intake (it's not much different than the stock GM intake) and opt for the Edelebrock RPM (high rise) intake.

Top that with either an Edelbrock 600cfm carb or a Holley carb. I've used both and prefer the Holley for performance although I think the Edelbrock is easier for initial adjustments.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 03-01-2007, 02:02 PM
Mertz's Avatar
Registered User
Join Date: Jun 2002
Location: Reardan, WA
Posts: 702
Wiki Edits: 0

Thanks: 1
Thanked 5 Times in 5 Posts
Here is what I have done so far on a budget.

Ceramic coated headers dual exhaust
Edlebrock Performer EPS manifold
Edlebrock 600 cfm carb
1" alum carb spacer
MSD ignition
New wires
1.52 Comp Cams roller tip rockers (not driven this mod yet)
Raptor mufflers
Shift kit in the 350 tranny
Timing set at 14 initial about 36 total plus vacuum (I tried both ported an manifold, manifold got hard to start with all the advance.)

This is all on a stock 72 350. Not all produced a noticeable difference. I was surprised how much the spacer seemed to increase my get up and go. $10 on ebay.

I have plenty of power and decent fuel economy. My attempt in all these mods was not horsepower but engine efficiency to try to gain better fuel economy. I bought a lot of stuff on ebay to keep costs down.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Please select your insurance company (Optional)


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Bog/Black Smoke on Olds 350 at 3000 rpm JohnTN Engine 4 03-17-2009 11:39 AM
possible 350 block purchase - comments please idrva55 Engine 17 12-09-2007 09:29 PM
Crate 350 vs. crate 350 JohnnyGTO Engine 7 05-02-2004 11:33 AM
Intake + Carb for 305HO then to built 350 (74') leroytitman Engine 10 02-26-2003 02:35 PM
455 olds performance upgrades jjjjrau Engine 2 08-24-2002 12:37 PM

All times are GMT -6. The time now is 02:13 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.