260h in stock motor

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Yogi
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260h in stock motor

Post by Yogi »

Just a quick question, guys. My 79 is bone stock except for a 2.5 inch exhaust pipe. Don't know anything about the muffler or cat. How much improvement can I expect by only dropping in a comp cams 260h and nothing else? Can't say I could do many other simple mods to improve performance, since emissions testing is a thing around these parts. 4 barrel is out of the question.
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Stuka
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Re: 260h in stock motor

Post by Stuka »

A larger cam could potentially hurt your emissions tests. Although the 260H is probably mild enough to not cause any sort of idle test issues.

It will still add performance, even with a 2v carb. An edelbrock intake (with 2v adapter) would make its gain more noticeable. 2.5" exhaust will be fine for a 2v carb at the RPM that your engine will see.

Also, as part of switching out the cam, you will need to do lifters/pushrods at the same time.
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weeegoneeer
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Re: 260h in stock motor

Post by weeegoneeer »

I'm running a 260H with 4 barrel, performer intake with no EGR & pass emissions under Oregon DEQ.
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Yogi
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Re: 260h in stock motor

Post by Yogi »

Whoa, weegoneer! That's great to hear! What kind of carb? I'm very surprised. I'm in Oregon, also. I know we're not as strict as Cali, but still surprising!

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Re: 260h in stock motor

Post by sirrus »

With a stock everything and after proper tuneup I was able to pass Oregon DEQ (Portland metro area) with flying colors.

Here is first test (failed)
Image

And final (after carb rebuild and tuneup)
Image

I’m no expert on cams, but given these numbers with stock config I doubt that new cam alone could fail your DEQ test if everything else is in order
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Yogi
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Re: 260h in stock motor

Post by Yogi »

Muchas thank yous, amigo.
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fulsizjeep
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Re: 260h in stock motor

Post by fulsizjeep »

I put a 260H in the 401 when it was prepped for my GW in 2004. The other change was installing an Edelbrock SP2P with an AFB carb. 10 years ago I switched over to a 670 cfm Holley Truck Avenger. I don't have to deal with emissions but the engine is still running pretty good after all these years.
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Yogi
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Re: 260h in stock motor

Post by Yogi »

How do you think the 260h effects the 401 vs the 360?
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fulsizjeep
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Re: 260h in stock motor

Post by fulsizjeep »

To be honest, I don't know. I haven't had a running 360 in a good while. When you put a new cam and lifters in a used motor, you never know what you might get. It would depend on wear and tear on the rest of the motor.
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tgreese
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Re: 260h in stock motor

Post by tgreese »

One would expect a given cam to be milder in the 401 than the 360, because of the increased displacement. That's just the conventional wisdom - I have no experience with this question.
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Re: 260h in stock motor

Post by weeegoneeer »

Yogi! Just checking back in here & saw your question. Am running a Holley SA 670 (I think it's too big) with edelbrock performer no EGR manifold.
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Yogi
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Re: 260h in stock motor

Post by Yogi »

Gracias, amigo!
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