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  • 1965 - 1973 Classic Mustangs -General/Talk-
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Anyone wanna give me a estimate?

  • Thread starter Thread starter Zer0
  • Start date Start date Apr 2, 2007
Z

Zer0

New Member
Oct 4, 2005
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California
Apr 2, 2007
#1
  • Apr 2, 2007
  • #1
How much hp would I be looking at if i would get some new heads,4 bbl carb, and exhaust for my 260?
 

xoxbxfx

Founding Member
May 9, 2001
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Southlake, TX
Apr 2, 2007
#2
  • Apr 2, 2007
  • #2
not much... Im going to say max 290hp
 
6

6T6coupe

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Jul 15, 2000
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Apr 2, 2007
#3
  • Apr 2, 2007
  • #3
Not many aftermarket heads will work on a small bore 260. The valves simply won't clear.
 

rbohm

Founding Member
Apr 12, 2002
6,698
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204
tucson,az
Apr 2, 2007
#4
  • Apr 2, 2007
  • #4
Zer0 said:
How much hp would I be looking at if i would get some new heads,4 bbl carb, and exhaust for my 260?
Click to expand...

just heads, intake and carb, and dual exhaust? a stock 260 grosses something like 165hp, so i would say you might hit about 200hp at the flywheel net(gross about 230hp) at best.
 
Z

Zer0

New Member
Oct 4, 2005
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Apr 2, 2007
#5
  • Apr 2, 2007
  • #5
heh, thats pretty pathetic...I could get more power by swaping in a freakin honda engine....

well anyone know if i were to swap in a 5.0/t5, would there be any cutting involved? Don't really want to do anything anymore that i cant reverse in the future....
 
B

BornInAFord

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Apr 22, 2005
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Bend, OR 97701
Apr 2, 2007
#6
  • Apr 2, 2007
  • #6
Don't count the 260 out entirely. Early production Cobras (the first 75 made) got 260HP (old horsepower value, but still...) out of the 260, and I'm confident an updated cam, decent headers and 1.7 roller rockers you could equal or better that output. Preproduction versions got 325 horses out of the 260 (yes, the 260!). You are stuck with the existing heads, but may be able to port them and also use a good intake and headers that are designed for the 289/302. Now, if you had a 221, then you may be out of luck!

Daniel
 
B

BornInAFord

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Apr 22, 2005
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Bend, OR 97701
Apr 2, 2007
#7
  • Apr 2, 2007
  • #7
no cutting and wherever a 260 would bolt, a 289, 302 or 5.0L would fit.

The 260's downside is the aftermarket support and the 5 bolt bellhousing issue. It's a good engine that can be built up some (supercharger or turbo would be trick) and will last a long time when done up right. The 260 was also used in the Sunbeam Tiger, where, with the light weight it excelled in racing. The Cobra with the 325 horse 260 could do 0-60MPH in 4.2 seconds and over 140MPH. Try that in a freakin stock Honda...
Daniel
 
T

tylerrocks

New Member
Oct 13, 2005
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Big Spring, TX
Apr 3, 2007
#8
  • Apr 3, 2007
  • #8
I was in your boat not too long ago...wanted to upgrade my 260. It's just not worth it. I bought a roller 302 block and havn't looked back. Plus I still have my semi-rare 260 intact. A budget 302 will grant you 300 horses easy, it's fun and thats where I started. Now I'm lookin at 347 kits and Vic Jr heads.
 
H

Helmantel

New Member
Aug 9, 2006
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Apr 3, 2007
#9
  • Apr 3, 2007
  • #9
6T6coupe said:
Not many aftermarket heads will work on a small bore 260. The valves simply won't clear.
Click to expand...

The 260 had 1.59" intake and 1.39" exhaust valves and a 3.80" bore.

On 4" bore engines you can go all the way to 2.02 intake valves (with inline valves). On a 260, you have 0.10" less bore on each side, so theoretically, if a 2.02" valve fits a 4.00" bore, then a 1.82" valve would fit a 3.80" bore.

I don't know how it works out in practise, but I don't think you're limited to the stock valves. Stock 289 heads with 1.78/1.48 probably fit fine and the 54cc would not reduce compression ratio too much either (and may even increase CR after milling them). They're not exactly high flow heads either, but can be improved with some porting.

Maybe even 1.84"/1.54" valves (stock 351W) would fit but most stock heads with those valve sizes (351W, cast iron GT40, GT40P) have rather large compression chambers, which would result in a very low compression ratio when used on a 260. You could of course machine 289 heads for these valves.

OK, it doesn't make much sense to use a 260 as a base for a performance engine, but then again, we're not in this hobby because it makes so much sense . It would be nice to see a suprisingly powerful 260 for a change.
 

1320stang

Founding Member
Nov 13, 1998
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89
Edmond, Oklahoma
Apr 3, 2007
#10
  • Apr 3, 2007
  • #10
Yeah, I'd pull the 260 and slap a 289-302 in there. If the car is pretty cherry, you might want to keep the engine to put back in. You could try and find a 5 bolt 289 block to build a anything from a 289 up to a 347 out of but you're really better off putting in a 6 bolt block. If you have a C4, you can change the bellhousing to a 6 bolt easily enough. In fact, if you have a 5 bolt C4 bell, I have a friend that's looking for one.
 
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