| OSO Sponsor |
 |
| OSO Sponsor |
|
|
|
|
|
 |
02-13-2008, 11:22 PM
|
#1
|
|
Registered
Join Date: Sep 2007
Location: Deltona, Florida
Posts: 84
86 Wellcraft Nova 23
|
how can you tell the diffrence?
Between a regular 454 and a 454 mag, i have the black cap that goes over the carb, but it dosnt have any thing on its just plain black, the previous owner really didnt know just knew it was a 454
there any like special serial numbers or ways to tell with out having it dynoed
|
|
|
|
02-13-2008, 11:55 PM
|
#2
|
|
Registered
Join Date: Sep 2007
Location: Deltona, Florida
Posts: 84
86 Wellcraft Nova 23
|
thanks for the info
|
|
|
|
|
02-14-2008, 09:21 AM
|
#3
|
|
Registered
Join Date: Jun 2004
Location: Wichita, KS
Posts: 471
1989 Chaparral Villain III
|
Pull the valve covers and check the head casting numbers.
|
|
|
|
|
02-14-2008, 09:51 AM
|
#4
|
|
Registered
Join Date: Aug 2006
Location: Colonial Beach VA
Posts: 631
1988 251 convincor with a BBF , yea a 460 ford !!
|
Look at the intake runners , mag will be squared off and you cant see much of the head where the intake bolts up , non-mag has peanut port heads and you can see alot of the intake face side of the head , just for grins , look for the red sticker on the starboard (driver side) valve cover , if it says its 330hp its non-mag , 365/385 and its a magnum
|
|
|
|
|
02-14-2008, 10:09 AM
|
#5
|
|
Current Obsession
 Platinum Member
Join Date: Aug 2005
Location: HOUSTON ,TX
Posts: 8,699
91 Scarab 21' Excel/1999 Proline 200 sport
|
Quote:
Originally Posted by fredefox
Mag has 4 bolt main bearing caps and the non mag has two bolt main caps.
|
Thats not true, I have a 330 and it was a 4 bolt main.
Just above the starter there should be a plate with the serial number on it.
Post that # and im sure someone can look it up for you.
__________________
IS THAT BAD
My favorite color is clear
CAJUN COWBOY
|
|
|
|
|
02-14-2008, 11:15 AM
|
#6
|
|
Registered
Join Date: Feb 2003
Location: Ormond Beach, FL
Posts: 67
|
Quote:
Originally Posted by BY U BOY
Thats not true, I have a 330 and it was a 4 bolt main.
Just above the starter there should be a plate with the serial number on it.
Post that # and im sure someone can look it up for you.
|
Agreed, I have a '96 7.4L and based on the block casting number, 10237297, it's a 4 bolt main. The biggest difference between the 7.4L (454) and the Mag is forged crank (and rods, I think), large port heads (rectangular GM vs. small port oval GM, both are cast iron) and tall intake.
|
|
|
|
|
02-14-2008, 11:29 AM
|
#7
|
|
Registered
Join Date: Jun 2004
Location: Wichita, KS
Posts: 471
1989 Chaparral Villain III
|
Quote:
Originally Posted by mjw930
Agreed, I have a '96 7.4L and based on the block casting number, 10237297, it's a 4 bolt main. The biggest difference between the 7.4L (454) and the Mag is forged crank (and rods, I think), large port heads (rectangular GM vs. small port oval GM, both are cast iron) and tall intake.
|
Don't forget cast vs forged pistons...which are the weakest link in the 7.4.
|
|
|
|
|
02-14-2008, 01:19 PM
|
#8
|
|
Registered
Join Date: Sep 2007
Location: Deltona, Florida
Posts: 84
86 Wellcraft Nova 23
|
thanks for the replys guys ill have to check it all out, i dont store the boat at my house anymore so ill have to check it next time i see it.
|
|
|
|
|
02-16-2008, 09:01 AM
|
#9
|
|
Gold Member
 Gold Member
Join Date: Oct 2000
Location: Western Michigan
Posts: 4,079
A boat?....What boat??? How about a galvanized warsh tub wit a tornady strapped own da rear!
|
Quote:
Originally Posted by BY U BOY
Thats not true, I have a 330 and it was a 4 bolt main.
|
I'm pretty sure the Merc 330hp/454cid originally was designed with a 2-bolt main block with all cast parts. It was in the late 1980's or so that the 330 came with a 4-bolt block vs a 2-bolt, but still had cast parts.
__________________
Thank God for the U.S. Marines!
Hey, I'm still learning! ;)
|
|
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
