Engine Mods Outrageous Builds, High-Horsepower Modifications, strokers, and big cams for the Corvette

GM Mercruiser question

Thread Tools
 
Search this Thread
 
Old Sep 7, 2009 | 01:41 PM
  #1  
ZLX's Avatar
ZLX
Thread Starter
Instructor
 
Joined: Jan 2009
Posts: 144
Likes: 0
From: Go'n 2 Surf City.. it's 2 to 1
Default GM Mercruiser question

I am putting an Iron Duke 4 cyl in a flat fender jeep.. I love the little Iron Duke.. 3in stoke x 4 inch bore.. Pontiac 301 rods..

Mercruiser used the Iron Duke for a number of years as an I/O power unit.

I have noticed a 3.0 Mercruiser 4cyl of the same vintage.. bore is the same but stroke is 3.6 ... is this a stroker Iron Duke?, or a different block?...

3.0 Mercruiser info is not plentiful on the net... was curious about stroking my Iron Duke..

I realize this is a tad O/T.. just can't find good info on the 3.0 merc.

Anyone have info on the 3.0??
Reply
Old Sep 10, 2009 | 01:27 PM
  #2  
rklessdriver's Avatar
rklessdriver
Safety Car
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Apr 2005
Posts: 3,624
Likes: 431
From: Dale City VA
Default

The 3.0L is a totally different block.

It has a SBC bellhousing pattern.

Few other dofferences in it and the 2.5L Iron Dukes.

The 3.0L uses a SBC (1pc) crankshaft flange and bolt pattern.

The 3.0L uses an odd ball 1.036" width rod that is 5.7" (stock SBC) long.

Being that the most common Jeep engine swap adapters are for a SBC, if you can find a complete good running fresh water 3.0L, IMO it would be a good and easy swap into an early M38 or M151 type Jeep. More power than a 2.5L but not near the imbalance of power and weight distribution that a V8 SBC would have in one.
Will
Reply
Old Sep 24, 2009 | 04:29 PM
  #3  
Dale1990's Avatar
Dale1990
Le Mans Master
20 Year Member
Active Streak: 30 Days
All Eyes On Me
Liked
 
Joined: Apr 2002
Posts: 5,726
Likes: 46
From: Waukesha WI
St. Jude Donor '15
Default

Originally Posted by rklessdriver
The 3.0L is a totally different block.

It has a SBC bellhousing pattern.

Few other dofferences in it and the 2.5L Iron Dukes.

The 3.0L uses a SBC (1pc) crankshaft flange and bolt pattern.

The 3.0L uses an odd ball 1.036" width rod that is 5.7" (stock SBC) long.

Being that the most common Jeep engine swap adapters are for a SBC, if you can find a complete good running fresh water 3.0L, IMO it would be a good and easy swap into an early M38 or M151 type Jeep. More power than a 2.5L but not near the imbalance of power and weight distribution that a V8 SBC would have in one.
Will
Good info! I have Four Winns runabout with a 3L and I was always a little curious if it was related to the 2.5. Now that I know it has the same Bellhousing crank bolt patterns I might be in trouble.
Reply

Get notified of new replies

To GM Mercruiser question





All times are GMT -4. The time now is 09:32 AM.

story-0
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-1
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-2
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE
story-3
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-4
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-5
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-6
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE
story-7
10 Revolutionary 'Corvette Firsts' Most People Don't Know

Slideshow: 10 Important Corvette 'firsts' that every fan should know.

By Joe Kucinski | 2026-04-29 17:02:16


VIEW MORE
story-8
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE
story-9
2027 Corvette vs The World: Every C8 vs Its Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-24 16:12:42


VIEW MORE