How much power will I lose?

[rallye72]

I have a 360 .030 over 10 to 1 compression, J-heads with 2.02 / 1.60 valves, air gap with eddy 750 carb, comp cams xe 262. What I'm going to swap on will be J-heads with no port work and 1.88/ 160 valves, cast iron 340 factory intake, 340 a-body exhaust manifolds, and probably a thermoquad off an early 70's 440.
What happened is the wife got her wish and I sprung for a 340 and want to use her top end off the 360. Now I have a 360 short block with only 2500 miles on it and will either keep it as a spare or will donate it to a friends A-100 van. I just want to see what removing the headers, big valves, and airgap intake will kill this 360. Any guesses?

[TK]

IMO, it will run better, at least for the first 5000rpm.

[dwc43]

Originally Posted by rallye72

I have a 360 .030 over 10 to 1 compression, J-heads with 2.02 / 1.60 valves, air gap with eddy 750 carb, comp cams xe 262. What I'm going to swap on will be J-heads with no port work and 1.88/ 160 valves, cast iron 340 factory intake, 340 a-body exhaust manifolds, and probably a thermoquad off an early 70's 440.
What happened is the wife got her wish and I sprung for a 340 and want to use her top end off the 360. Now I have a 360 short block with only 2500 miles on it and will either keep it as a spare or will donate it to a friends A-100 van. I just want to see what removing the headers, big valves, and airgap intake will kill this 360. Any guesses?

At least a good 50 to 75 horses at the least. Just swap in the bigger valves and mill he heads a bit before you install them.

[rallye72]

I'm not really looking for performance, Just want to put my leftover stuff to good use. Thanks

[TK]

You wont notice the difference between the big and small vaves on that engine, trust me!

15HP.

[B1owner]

Originally Posted by dodgetruckboy

You wont notice the difference between the big and small vaves on that engine, trust me!

15HP.

Yes. you will.

[TK]

OK

[B1owner]

Originally Posted by dodgetruckboy

OK

no offensine man.

[TK]

None taken.
I swapped out a set of 308 1.88 heads for 308 2.02 heads on a 360, and didnt notice any difference what so ever.
J's might be different.

[rumblefish360]

Originally Posted by rallye72

I have a 360 .030 over 10 to 1 compression, J-heads with 2.02 / 1.60 valves, air gap with eddy 750 carb, comp cams xe 262. What I'm going to swap on will be J-heads with no port work and 1.88/ 160 valves, cast iron 340 factory intake, 340 a-body exhaust manifolds, and probably a thermoquad off an early 70's 440.
What happened is the wife got her wish and I sprung for a 340 and want to use her top end off the 360. Now I have a 360 short block with only 2500 miles on it and will either keep it as a spare or will donate it to a friends A-100 van. I just want to see what removing the headers, big valves, and airgap intake will kill this 360. Any guesses?

IMO, and just my opinion dispite whats being said here;
The 2nd set up with 1.88's and 340 intake will feel better, get more MPG's with better throttle response. In a tamer way. The headers will cut out some power. You should notice the difference in the change of parts.
The cam is small. The 2nd set up should be more in line with the cam.
My question is ....Is the intake a T-Q intake?
Sorry. No guess on HP loose.

[rellik eeb]

Originally Posted by dwc43

At least a good 50 to 75 horses at the least. Just swap in the bigger valves and mill he heads a bit before you install them.

Right on the Money.

Most of the power loss IMO will come from the intake swap, and headers loss. Id say 30-35 horses give or take a few on these changes alone. You didnt clairfy which size headers and which intake was on the now, so its hard to say. Pickup a good reccomended intake, and at least a set of 1 5/8 headers and gain most of it back. Open the heads up for some good bowl blending, and some guide boss stream lining (exhaust side more so) and gain most of it back. Even with the smaller valves I dont see you lossing a ton, but again, I take it that the orignial heads have some good port work, so who knows??

Maybe 15 horse as stated before.

[TK]

I still say with the cam he has, the intake and heads arent going to make much of a difference....................
Headers may a bit...........but only on the top end..............
Only one way to find out.
Get R Done Rallye!

[rallye72]

The intake I'm going to install is off a very early 340, block was cast june 6 1967. I'm using the intake off it. Its cast iron and it sits almost as tall as my eddy airgap and has a holley carb. I may very well stick with headers on it.

[TK]

Well? Get On It! Would only take me about 6 hours....................

[rallye72]

Originally Posted by dodgetruckboy

Well? Get On It! Would only take me about 6 hours....................

Look little mister, I will be building two 340's and a 360 at the same time. Yea, the job would take 6 hours if you were hold the flashlight for me
I can't get the 360 out while the wife is driving it!

[TK]

I would be half done by now................................ :flip:

Not really, a head swap takes me more than 6 hours, I was just kidding.

[Rust collector]

That is because you have to stand on a milk crate to reach over the fender.
:flip:

[TK]

Not on the puny little cars you guys drive! :flip:

[dwc43]

Stop being so simple Tk and just admit your short and get it over with.

[Rust collector]

Originally Posted by dodgetruckboy

Not on the puny little cars you guys drive! :flip:

Wow! you must have grown a lot lately.
The last few days, the "car" I have driven says euclid on the front...
Not really big, but damn tall anyway.