small block question

W

willowbilly3

Well-known member
Can I run GT40-P heads on my 260 without the valves hitting the block? I picked up another good 260 today and plan to start rebuilding it for my rpu and I'd like better heads.
 
The GT40p heads have pretty small valves so may work. Lay a 260 head gasket on a GT40p head to get an idea of what's going on. You may need to mill the heads to get compression back, too. As I remember, GT40p heads are 58-60 cc's and 260 heads are around 54 cc's.
Don't forget spark plug location! GT40p's have relocated spark plugs and might interfere with the exhaust manifolds (or headers). If you can, bolt your exhaust to the GT40p heads and check for plug interference before you buy the heads. I had a set on my 289 '67 Cougar with long tube headers and I had to cut the flanges off an old set of headers to space the headers 3/8" further out, had to buy 7 shorty header plugs from Accel at $14 each (only ones I could find), and had to flip 4 plug wires end-for-end because the nice thick boots hit the headers. The thin nipples on the distributor end, when put on the plugs, gave enough clearance that the wires didn't burn. Custom headers to fit the Cougar with GT40p's were over $600!
 
Good to know, thanks. I don't have a set I can lay my hands on right now. Maybe I should settle for a set of the E7 heads. I guess I'll have to see what I can find for pistons when I get into it. If stock pistons is all I can find I'll probably just try to open up the stock heads a little.
 
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if you plan on boring the block go to .060.you need all you can get from these small engines.walls are plenty thick.
 
The one I'm running now is bone stock except for the 2 two barrels and the roadster pipes. It scoots the little 1900# car along pretty well. No problem whistling right past 100 in 4th, never tried to get to the top of 5th yet. I could easily go with a 302 but I kinda like obscure stuff that you don't see anyone else using.
 
If your new engine will run a stock or nearly stock cam, I say keep the original 260 heads and do a mild clean-up porting job with a 5 angle valve job. There are porting how-to articles with photos on the internet. With only 260 or so cubes and a mild cam, you won't need big ports and valves anyway. In fact, the smaller ports will give you better mid-range power anyway.
 
Yeah 40, I've had a couple others say the same thing. I've done a couple light port jobs and understand the basics of a good clean up. It sure did wake up the 300-6 I did it to a few years back. I was just thinking I needed to step up to heads with hard seats. And I was planning to cam it a little, nothing wild though.
 
willowbilly3 said:
The one I'm running now is bone stock except for the 2 two barrels and the roadster pipes. It scoots the little 1900# car along pretty well. No problem whistling right past 100 in 4th, never tried to get to the top of 5th yet. I could easily go with a 302 but I kinda like obscure stuff that you don't see anyone else using.
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I don't know about anyone else but I'd enjoy seeing some pictures of your car. :)
 
Here's a little better picture of the engine and my home made 2 deuce set up. Both are the little .98 Motorcraft 2100s. The wiring got cleaned up quite a bit after this picture.

 
Here's a fuzzy picture of the frame. I used 1/4 elliptical springs with a triangulated top bar set up. It works real well.




Front axle is econoline, narrowed about 3". Brakes are pretty much home made brackets, S10 calipers and Aerostar rotors over the stock econoline hubs.

 
willowbilly3 said:
Here's a little better picture of the engine and my home made 2 deuce set up. Both are the little .98 Motorcraft 2100s. The wiring got cleaned up quite a bit after this picture.

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curious what are those tubes at base of carbs for?.that looks like a fun car
 
willowbilly3
That's a lot of serious work you put in on that truck. Did you design the rear suspension?

willowbilly3 said:
..... but I kinda like obscure stuff that you don't see anyone else using.
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Here's another one... that got away. (yours reminded me of it, cuz it also had a 260)

A while back I went to a guy's shop to ask about y-block parts for the '55 I had just bought, and he had this sitting in the middle of the floor. I thought it was pretty cool and tried to ignore it for about a month.... until I couldn't stand it any more, called him up and asked what he wanted for it. He had already sold it for $1500.
 

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Thanks Jeff, I had that bookmarked once and lost it.
The tubes are the old coolant heated carb spacers. I needed one inch spacers and couldn't find any other ones.
And yes, I did design the rear suspension. I tried to build the whole car in the spirit of the 50s where you used junk yard parts and made them fit. The top links were a tie rod from a Massey Harris combine. The leaf springs are 46 Ford pickup fronts and one 39 IH leaf because they are thicker and just what I needed to tune the ride height. The tub is a 29 4 door cowl I reworked and a 26-27 touring back. I used some 23-24 touring rear doors and reworked them to fit, then built the rest.
The lower part of the intake is 88 Crown vic 5.0. I machine the dividers down as far as I could to make some plenum area and built the adapter plate with a hole saw in the drill press. I also had to weld the front of the coolant passages shut a little because they hang over the 260 heads. They actually work pretty good but with no carb heat, it has a little flat spot until it's warmed all the way up but I have manual chokes so I can keep it a little rich if I need to. I used a couple 352 pickup carbs to get the manual choke stuff from.
 
Also I built my own adapter plate and run a t5 from an 89 Mustang, I think it was a V6 or a 4 banger, the one with pretty deep low. Rear end is 57 car 9 inch.
 
willowbilly3,

I think you've defined the meaning of hot rodding, far beyond what most of us have. I really liked the part about the intake manifold. Salute!
 
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