396/325hp - Chevelle Tech
Engine General Engine Discussion.

 13Likes
Reply
 
LinkBack Thread Tools Search this Thread Display Modes
post #1 of 16 (permalink) Old Mar 27th, 20, 7:17 PM Thread Starter
 
Join Date: Mar 2020
Posts: 4
396/325hp

I have a 1968 Chevelle ss stock 325hp
A guy has a aluminum intake date code correct for a 396/454 for round ports but I think my heads are oval, does it make a big difference
I want more horse power and was going to change intake anyways, would these be a could consideration
Thank you
Doug/chevelle is offline  
Sponsored Links
Advertisement
 
post #2 of 16 (permalink) Old Mar 27th, 20, 7:47 PM
Lifetime Premium Member
Guy
 
Join Date: Dec 2006
Location: Nova Scotia Canada
Posts: 2,467
Garage
Re: 396/325hp

Round and oval port heads are quite likely the same thing.
There are 3 general head/port shapes for the BBC;
Peanut port and oval and rectangular port.
If you provide part or casting numbers that would help determine what parts you have.
Guy
Steve R likes this.

'86 Monte SS,
513 Stroker,
AFR CNC'd 315 heads,
Custom Bullet solid roller,.706, 285/293-255/263 @ .050,110 LSA,UDHarold's lobes.
Isky .904 EZX Roll lifters,
Thanks to Mike "Wolfplace" Lewis,
Weiand Stealth intake,ported & gasket matched,
825 Mighty Demon,tuned by jmarkaudio,
2 inch Hooker Headers,(Coated),
Doug Nash 4+1 5 speed,w/a couple of cryo treated gears,
9 inch rearend,
Hurst Vertical Gate II In Line Shifter,
TC Member # 4921
GuysMonteSS is offline  
post #3 of 16 (permalink) Old Mar 27th, 20, 7:52 PM
Senior Tech Team
 
Join Date: Apr 2005
Location: Fountain Hills, AZ
Posts: 1,664
Re: 396/325hp

I don't think Chevy ever made an aluminum BB intake other than square port or for a Quadrajet.
Jerry70 is offline  
 
post #4 of 16 (permalink) Old Mar 27th, 20, 7:57 PM
Lifetime Premium Member
Ole
 
Join Date: Dec 2016
Location: NE Jefferson County, WA
Posts: 2,085
Garage
Re: 396/325hp

If this is a stock L35 396/325 the best way to add horsepower is a camshaft upgrade. The L35 was notoriously under-cammed and one can easily add 25-50 HP by changing camshafts. Be sure to upgrade valve springs at the same time. I also recall an untouched '68 L35 396 that I removed from a Caprice Wagon in the early 1980's that had 5/16" pushrods. If your engine has the same I would change those out for 3/8" also.

Oh, and welcome to Team Chevelle, Doug!
von, BRN2RUN and shovelrick like this.

First Posted to TC as Ole Birkland in Feb 1999
Aces 3383
1969 Chevelle SS396, L78, M22, KK 4.10 posi, F41, Blue Light Stereo, Tilt Column, Burgundy/Maroon w/Red Stripe, Black Bench Seat, PS,
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
PDB, American Torque Thrust & BFG TA's, fully restored.
Saltherring is offline  
post #5 of 16 (permalink) Old Mar 27th, 20, 8:01 PM
Lifetime Premium Member
Ole
 
Join Date: Dec 2016
Location: NE Jefferson County, WA
Posts: 2,085
Garage
Re: 396/325hp

Quote:
Originally Posted by Jerry70 View Post
I don't think Chevy ever made an aluminum BB intake other than square port or for a Quadrajet.
Back in 1970 I purchased an Edelbrock C396 oval port manifold for my '68 L34 Chevelle. It was machined for square-bore carbs, not spread bore.

First Posted to TC as Ole Birkland in Feb 1999
Aces 3383
1969 Chevelle SS396, L78, M22, KK 4.10 posi, F41, Blue Light Stereo, Tilt Column, Burgundy/Maroon w/Red Stripe, Black Bench Seat, PS,
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
PDB, American Torque Thrust & BFG TA's, fully restored.
Saltherring is offline  
post #6 of 16 (permalink) Old Mar 27th, 20, 8:09 PM
Lifetime Premium Member
jimmyradford
 
Join Date: Oct 2007
Location: ARKLATEX
Posts: 2,782
Re: 396/325hp

Quote:
Originally Posted by Saltherring View Post
Back in 1970 I purchased an Edelbrock C396 oval port manifold for my '68 L34 Chevelle. It was machined for square-bore carbs, not spread bore.

He's referring to the '68-69.5 Corvette L-36 intake. It's an aluminum, low rise spread bore to fit under the low hood line.
Steve R likes this.

TC Member # 4431
'16 GMC Denali XL- 6.2L's are sweet
'07.5 Chevrolet 2500HD-6.6 D-Max
'07.5 Chevrolet Suburban
'67 Chevrolet Biscayne- SS427 L-36/TH400 (Hers)
'67 Hell Camino-BB 427/TH400 (His)
'66 300 Deluxe 2 door-230/PG
"Good people sleep peacefully in their beds at night only because rough men stand ready to do violence on their behalf."-Orsen Wells

Strong people are harder to kill than weak people and they're generally more useful.
badrad is online now  
post #7 of 16 (permalink) Old Mar 27th, 20, 8:12 PM
Senior Tech Team
 
Join Date: Dec 2004
Location: tucson az
Posts: 14,296
Send a message via AIM to Jim Mac
Re: 396/325hp

I bought a winter's aluminum q jet intake at a swap meet awhile back. it was a marine intake with the brass liner under the thermostat housing. jim

Jim

70 chevelle, SS clone 454 4 speed
71 camaro. (owned since 1978!) 6-71 blown small block 400
66 chevelle 350 4 speed 3.55 12 bolt
66 el camino 350 th350 parts hauler
Jim Mac is offline  
post #8 of 16 (permalink) Old Mar 27th, 20, 8:23 PM Thread Starter
 
Join Date: Mar 2020
Posts: 4
Quote:
Originally Posted by Saltherring View Post
If this is a stock L35 396/325 the best way to add horsepower is a camshaft upgrade. The L35 was notoriously under-cammed and one can easily add 25-50 HP by changing camshafts. Be sure to upgrade valve springs at the same time. I also recall an untouched '68 L35 396 that I removed from a Caprice Wagon in the early 1980's that had 5/16" pushrods. If your engine has the same I would change those out for 3/8" also.

Oh, and welcome to Team Chevelle, Doug!
Thanks, I am having a hard time learning how to reply on here
Anyways casting number s are 3883948
And 3917213
Good to know about the cam
Doug/chevelle is offline  
post #9 of 16 (permalink) Old Mar 27th, 20, 8:26 PM Thread Starter
 
Join Date: Mar 2020
Posts: 4
Also the number for the intake is 3933163 code 2
Doug/chevelle is offline  
post #10 of 16 (permalink) Old Mar 27th, 20, 8:42 PM
Lifetime Premium Member
Guy
 
Join Date: Dec 2006
Location: Nova Scotia Canada
Posts: 2,467
Garage
Re: 396/325hp

I couldnt find anything that matches the first #.
The second shows as a cast iron intake for a 390 HP 427.
The third # is,IIRC,a Winters aluminum intake for the High Performance solid lifter 396,427 and 454.Rectangular port version.
Guy

'86 Monte SS,
513 Stroker,
AFR CNC'd 315 heads,
Custom Bullet solid roller,.706, 285/293-255/263 @ .050,110 LSA,UDHarold's lobes.
Isky .904 EZX Roll lifters,
Thanks to Mike "Wolfplace" Lewis,
Weiand Stealth intake,ported & gasket matched,
825 Mighty Demon,tuned by jmarkaudio,
2 inch Hooker Headers,(Coated),
Doug Nash 4+1 5 speed,w/a couple of cryo treated gears,
9 inch rearend,
Hurst Vertical Gate II In Line Shifter,
TC Member # 4921
GuysMonteSS is offline  
post #11 of 16 (permalink) Old Mar 28th, 20, 1:15 AM
Lifetime Premium Member
Dan
 
Join Date: Aug 2007
Location: orange county
Posts: 10,351
Re: 396/325hp

3883948 is a cast intake for a '67 vette or chevelle or Impala. Q jet of course.

'66 SS Chevelle
91 octane special
first day out
[email protected]
Stokerboats is offline  
post #12 of 16 (permalink) Old Mar 28th, 20, 5:25 AM
von
Lifetime Founding Member
Von
 
Join Date: Oct 1998
Location: Mooresville, IN (Indianapolis)
Posts: 14,529
Re: 396/325hp

Quote:
Originally Posted by Stokerboats View Post
3883948 is a cast intake for a '67 vette or chevelle or Impala. Q jet of course.
IMO you're wasting your time and money on a different intake for your 325 hp 396. The stock iron '68 intake isnt a bad piece and I doubt if there's much hp to be gained on an intake swap. Your time and money would be much better spent on the aforementioned cam and spring upgrade. In addition, carb and dist tuning, headers, exhaust, ignition also would bring a bigger bang for the buck. If you're keeping the stock snorkel type air cleaner, A few holes cut in the back side bottom, out of sight and outboard of the filter, will work wonders for upper rpm power and still be stock appearing to the casual observer.

von '69 Malibu Team Chevelle Member #15


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
von is offline  
post #13 of 16 (permalink) Old Mar 28th, 20, 8:31 AM
Senior Tech Team
 
Join Date: Aug 2018
Posts: 1,594
Swap distributer for Pertronics or MSD, adding a Holley DP, and headers helped me the most.

If you change to Winters intake w/rectangular ports you’re still choked off by little heads.
Reelysalty is offline  
post #14 of 16 (permalink) Old Mar 29th, 20, 2:26 PM
Tech Team
Dan
 
Join Date: Aug 2009
Location: Central NJ
Posts: 420
Re: 396/325hp

Quote:
Originally Posted by von View Post
IMO you're wasting your time and money on a different intake for your 325 hp 396. The stock iron '68 intake isnt a bad piece and I doubt if there's much hp to be gained on an intake swap. Your time and money would be much better spent on the aforementioned cam and spring upgrade. In addition, carb and dist tuning, headers, exhaust, ignition also would bring a bigger bang for the buck. If you're keeping the stock snorkel type air cleaner, A few holes cut in the back side bottom, out of sight and outboard of the filter, will work wonders for upper rpm power and still be stock appearing to the casual observer.
I agree, back in the day my buddy had a 69 Chevelle 396/325 . It ran 14.9 stock. Like everyone else back then his first mod was an aluminum manifold and holley carb . It then ran 15.0 - 15.1's . He installed headers and it went 14.9's . He then went BACK to cast iron intake and quadrajet it went 14.7's . He then swapped cam, lifters, v springs and it went 14.2's with no traction. The intake you have isn't that bad!It was the cam that was the weak link, even the 396/350 cam was VERY mild!
von and Georgia69 like this.
BRN2RUN is offline  
post #15 of 16 (permalink) Old Mar 29th, 20, 2:48 PM
Gold Member
Freddy
 
Join Date: Aug 2001
Location: Jacksonville, NC
Posts: 12,849
Re: 396/325hp

Welcome to the site.

Freddy
Freddy Mercado is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Chevelle Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address. Note, you will be sent a confirmation request to this address.

Email Address:
OR

Log-in










Thread Tools Search this Thread
Show Printable Version Show Printable Version
Email this Page Email this Page
Search this Thread:

Advanced Search
Display Modes
Linear Mode Linear Mode



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

 
For the best viewing experience please update your browser to Google Chrome