258 with a .30 overbore build up debate...

[1982AMCCONCORD]

Hello to everyone.

I JUST got done reading olymunch's entire thread and I realized that I am at a similar place as well but my engine is set up a bit different already.

I have a 1982 Concord and yesterday I had the Cat convertor replaced. Low and behold the original was clogged. They told me that since it was so clogged... I blew out part of the header gasket on the exhaust manifold nearest to the firewall. So now I am at a cross road... do I just fix it up and install a 2100/2150 carb or do I swap to a 4.o head, a clifford 4 barrel intake and a Renix exhaust manifold??

Back story: Many years ago... I had the engine rebuilt with .30 overbore, a bigger camshaft and stiffer springs in the head. I can't remember the EXACT mileage I had the engine rebuilt but I estimate the engine has around 20K or so miles on it. So... I don't feel that I need a whole new engine. Here's the thing though... not long after it was rebuilt... it got parked for about 6 years. Later on... after I had some money.... I took it to a shop because the fuel pump had seized and the brakes were all frozen as well. They got it all running again... and its seen a little road time but it still needs a lot of work.

Anyway... little by little I have done some work to it and the engine definitely runs strong. I took the AIR injection stuff off of it and all of the associated vacuum lines. I also had the crappy Carter carb tuned out a bit better and the thing runs better then it has in a long long time. So basically... I think its a good candidate for a 4.0 head, 4 barrel intake and a 2100/2150 barrel carb.

Here's the thing... I don't want to tear apart the intake and exhaust manifold to fix the exhaust gasket leak and then put the old stuff back on when I could just put a 4.0 head on... upgrade the intake and exhaust then put the MC2100/2150 on it. Does this sound like a good plan to you guys? I think its a reasonable approach. The ONLY reason I would keep the original head and stock intake/exhaust is due to overall cost. If it turns out to be substantially cheaper... then I would just replace the gasket, get the 2 barrel carb, a TFI upgrade and just be happy with it for a while.

So basically if you guys could help me chat this out a bit like you helped olymunch out... I WOULD really appreciate it a lot.

John

[captspillane]

The Clifford intake manifolds are overrated. It was the whole reason I have my Spirit. The previous owner did exactly what you're planning to do and then beat his head against a wall until he sold it to me for a great loss. In that sense I'm glad that chunk of junk came with it.

First problem was that he used the exhaust/intake gasket that came with the 1992 era 4.0 headers, specifically the stainless steel brand new ones available for $80 on ebay. I like the headers alot and have purchased another set. The catch is that you cannot use the gasket the headers are shipped with. Within a 100 miles of installation the thick gasket developed huge cracks and simply disintergrated. There was gaping holes along the entire gasket.

After replacing the gasket with a regular Felpro one, the engine still ran terribly. From there I realized that the previous owner bought a universal adaptor instead of the one specifically sold by Clifford. There is no universal adaptor that will work on the clifford intake. None. The ones that look like they would have a half moon along the mounting surface that overlaps the manifold and creates a hole the size of a pencil lead. Since the hole was underneath the carb and the adaptor seemed to be perfectly fine, this was a nightmare to figure out.

After fixing that the 2150 still ran like total junk. I put a brand new one on and it improved, but still didn't run right. The timing was a total mess. I found out that the screw retaining the distributor was loose. Even fixing that and getting it timed didn't fix its terrible advancement issues.

At this point new leaks developed in the intake gasket. Turns out the Clifford chunk of junk is a different thickness than the headers. Since the bolts securing them bridge both, the bolts were cocked to one side and not effective in keeping steady pressure on the gasket, causing it to fail prematurely. At that point the whole system got ditched.

If you have a 4.9 stroker with an absurd compression ratio running NOX and producing 400 plus HP, then the Clifford intake is the way to go. Otherwise the extra volume of air does not have any performance bonus. The stock intake manifold works perfectly fine for TBI or a Motorcraft 2150. The Clifford intake is a total waste of money and could cause you to gauge your eyes out in frustration.

[1982AMCCONCORD]

OK thanks for the input but does the stock intake go on the 4.0 head?

Is it the same problems on the Offenhauser intake too?

[mudkicker715]

There are ways to oercome the intake problem. i have done it. others have done it. and as long as jeepers play with there jeeps ot will work. all i am saying is to bridge the gap is just a minor creative solution that is done a few different ways.

[priya]

My clifford intake and holley 4 barrell runs super nice.

[1982AMCCONCORD]

This is why I ask about it... at the last AMC show here in Kenosha... there were quite a handful of guys I had met with mod'd 258's and they most had the Clifford manifold. Two guys were pushing the 258 head. One had the Offy and the other had the Clifford intake. One was in a Spirit and the other was in a Gremmy. The others had the 4.0 head and a few of them had a 4 barrel while the other had the MC 2100/2150... none of them complained about it. I took at ride in the Gremmy with the 258 system and a Holley 500 and it was a kick in the pants. I was quite impressed and have been thinking about it ever since.

[1982AMCCONCORD]

My clifford intake and holley 4 barrell runs super nice.

Do you have the 4.0 head priya?

[mudkicker715]

I have a carbed stroker on one the other the same. both are 4.0 block and head. however to do that the intake is shifted around from where it would want to be, and the manifolds are different thickness than the intake. the first has many miles on it on and offroad. the second is almost ready to turn key. As far as aspiration i would love to throw a 4v at the first. Shaggimo did to a 4.0. It works. I seen a wrangler recently with the same type of setup it performed well on muddy hillclimbs. No bogging.

[1982AMCCONCORD]

Mudkicker... I want a carb... I have always liked FI but I want a carb on my Concord. I see SO MANY guys talking positive about their built up 4.2 and 4.0's but most have 4wd... I think mine would be cool as heck because mine is 2wd and wouldn't have the 4wd system taking residual power away. And I'm not looking for a screamer but I want the most power I can get for the least amount of money. (Don't we all.)

Most of my AMC friends tell me they'd do either... that overall the parts for these cars are pretty cheap when compared to other cars. Plus I want it to be a non typical fun to drive flash back of a car with some surprising power. I especially like that the straight 6 has so much TQ... I'm a big fan of 2wd TQ monsters.

[1982AMCCONCORD]

This is what I want my Concord to sound like:

http://www.youtube.com/watch?v=PJasB7typfw&feature=related

I don't have to have dual exhaust but I want it to sound as much like this as possible.

I like this video because its an 82 Eagle... and mine is an 82 Concord. The owner kept the stock 4.2 head... and I think it sounds great.

Clifford says that the 258 head will work well enough if its outfitted with larger valves... so the 258 head will work but they said that the 4.0 head is more desirable if more power is wanted in the future.

[carguy87]

A 4.0L head with 2.02 valves would give you plenty of power and help flow to give you a sweet exhaust note.  It'll also give you the option of going between multi-point FI and carb. without much effort.

[1982AMCCONCORD]

A 4.0L head with 2.02 valves would give you plenty of power and help flow to give you a sweet exhaust note.  It'll also give you the option of going between multi-point FI and carb. without much effort.

Thanks Carguy!!!