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Unread 09-07-2008, 04:39 PM   #1
Lawless_Jeep
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Anyone run the Clifford 6 = 8 performance for the 258?

I'm seriously looking at buying the intake manifold, dual outlet headers and cam kit from Clifford Performance. Just as soon as as the block gets to the machine shop this week and checked out, I'm going to order from Clifford. Has anyone used any of this stuff? They claim with the 264 cam, Holley 390 4-barrell on their intake manifold, headers and .060 milled from the head, you'll get 240 horse and 360 ft pds of torque. I'm thinking that'd be pretty wicked out of that six.
I'm just curious if anyone has used this setup, or recommends any other enhancements. And no, I'm not gonna run a stroker. I'm sick of hearing about stroker this and stroker that.

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Unread 09-07-2008, 04:44 PM   #2
jeepsr4ever
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That is a fantastic intake! You have to be carefull milling the head or your compression will make it so you will only be able to run race fuel.
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Unread 09-07-2008, 04:53 PM   #3
Lawless_Jeep
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Quote:
Originally Posted by jeepsr4ever View Post
That is a fantastic intake! You have to be carefull milling the head or your compression will make it so you will only be able to run race fuel.
Glad to hear the intake is a good one. I was stink-eyeing the Offy intake, but think I'll go with Clifford and keep everything a match. Thier headers matching up to their intake makes more sense to me that "hoping" the Heddman Hedders match up to the Offy intake. Could be just my simple way of thinking, I dunno.
Thanks for the imput.
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Unread 09-07-2008, 05:35 PM   #4
GPER
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My spare motor is 0.030 over with the 4.0 head, Crane torquer cam, with the Clifford intake for the 4.0 head. The exhaust is the somewhat stock 4.0 exhaust.
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Unread 09-07-2008, 07:09 PM   #5
Lawless_Jeep
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Quote:
Originally Posted by GPER View Post
My spare motor is 0.030 over with the 4.0 head, Crane torquer cam, with the Clifford intake for the 4.0 head. The exhaust is the somewhat stock 4.0 exhaust.
Have you ran this combination? How does it perform? Do you happen to have the specs on the Crane cam?

Thank you for your imput.
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Unread 09-08-2008, 05:05 PM   #6
Chrisfol82
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I ran their 4.0 head, intake and dual outlet header with the 264 cam. Its ran pretty good but the carb i had on it was too big. I had a 525 CFM and never got it tuned right. I have since switched to a 4.0 intake with fuel injection and EDIS spark controlled by megasquirt. I havent had it out to get it tuned quite right yet but it runs way better than it ever has. Im sure you could get it running pretty good with the carb too but mine just runs so much smoother with the fuel injection. I still have the 4.0 head, dual outlet header and 264 cam in it.

I dont know about HP numbers but id say its got to be close to that. It definately feels alot more powerful than any stock 4.0 so i would think it would at least be up over 210 HP or so.
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Unread 09-08-2008, 05:43 PM   #7
gosupes
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Not to rain on your parade, but...

I like the Clifford stuff, but I think they are misleading you at 360 lbs of torque. You have to remember the stock 258 was rated for something like 180 hp and at say 4500 max RPM, that would only get you 210 lbs of torque. I think you will probably end up closer to 220 HP and 260 lbs torque with the items you listed. The 258 head is the biggest obstacle to producing good power and it looks like you are leaving it on. I have the 264 cam, the Holley 390, the Clifford manifold and while it runs pretty good, it's not over 300# of torque. Also read up on exhaust and headers. The dual outlet headers can hurt your low end performance due to lack of scavenging and the 258 is a great low end motor. Clifford makes some good stuff and the people that work there are proud of their products, but I think they over sell the end result. The biggest improvement you can make is a 4.0 head. If you want to ad FI, great, more power, more economy, etc. Like carbs? Fine. Not as good as FI but way better than the 258 head. Either way, you miles ahead.
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Unread 09-08-2008, 09:13 PM   #8
Lawless_Jeep
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Quote:
Originally Posted by Chrisfol82 View Post
I ran their 4.0 head, intake and dual outlet header with the 264 cam. Its ran pretty good but the carb i had on it was too big. I had a 525 CFM and never got it tuned right. I have since switched to a 4.0 intake with fuel injection and EDIS spark controlled by megasquirt. I havent had it out to get it tuned quite right yet but it runs way better than it ever has. Im sure you could get it running pretty good with the carb too but mine just runs so much smoother with the fuel injection. I still have the 4.0 head, dual outlet header and 264 cam in it.

I dont know about HP numbers but id say its got to be close to that. It definately feels alot more powerful than any stock 4.0 so i would think it would at least be up over 210 HP or so.
Yeah, I think I'm going to stick with the Holley 390 cfm carb at the moment. I would've thought that anything over 450 cfm would be overkill.
I've had so many people tell me that I should inject the thing and be done with it. I've heard it's a pretty sweet deal, but I'm just not sure yet about doing that this time around. Hot rodding is all about playing around with combintations and experimenting.
Thank you so much for your input. Sounds like you've got a sweet setup.
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Unread 09-08-2008, 09:21 PM   #9
Lawless_Jeep
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Quote:
Originally Posted by gosupes View Post
Not to rain on your parade, but...

I like the Clifford stuff, but I think they are misleading you at 360 lbs of torque. You have to remember the stock 258 was rated for something like 180 hp and at say 4500 max RPM, that would only get you 210 lbs of torque. I think you will probably end up closer to 220 HP and 260 lbs torque with the items you listed. The 258 head is the biggest obstacle to producing good power and it looks like you are leaving it on. I have the 264 cam, the Holley 390, the Clifford manifold and while it runs pretty good, it's not over 300# of torque. Also read up on exhaust and headers. The dual outlet headers can hurt your low end performance due to lack of scavenging and the 258 is a great low end motor. Clifford makes some good stuff and the people that work there are proud of their products, but I think they over sell the end result. The biggest improvement you can make is a 4.0 head. If you want to ad FI, great, more power, more economy, etc. Like carbs? Fine. Not as good as FI but way better than the 258 head. Either way, you miles ahead.
Yeah, I was thinking that 360 ft pds sounded like quite a lot compared to the horsepower. I'm thinking that anything over the stock 115 horse is better than what I started with.
I've heard so much about the 4.0 head being better than the stock 258 head. When I bought the Jeep, I had larger valves installed and a little millwork. I think at this time, I'll keep the stock head and mess around with it a bit more before giving in to the 4.0 head. Just a little hot rodding in progress, and it's only money, right?
I've not heard anything about the dual outlet headers, so I'm a bit concerned that you say it can take away from the low end torque. I was planning to run a H-pipe just south of the headers. I'll need to do more research on my header choice now.
Thank you very much for the information.
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Unread 09-09-2008, 09:14 AM   #10
j33pman
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My Jeep came with the Clifford stuff on it. Don't know about the cam but I have the header, intake and valve cover. I took off as soon as I got it.
Intake is single plane meant for high speeds, I use my jeep for off-roading, not road racing so I considered it useless for me, although I do plan on re-using the header is possible with my 80's style aluminum intake if it will fit right.

The intake is doing a great job collecting dust. I would think about selling it, but I think shipping would be high, its kinda heavy, but if you want it PM me a fair offer, and I will find out how much the shipping would be
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Unread 09-09-2008, 06:02 PM   #11
gosupes
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Good point. Yeah the Clifford is a single plane, the Offy is the dual plane. As long as you keep the carb size reasonable and run a low RPM cam, the single plane manifold isn't as bad as you would think. I have never had the experience of driving a 258 motor with the Clifford setup, but the Clifford manifold on the 4.0 head is a pretty good combo.
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1986 CJ7, 4.2 w/4.0 head, TFI-HEI hybrid ignition, Clifford manifold w/Holley 390 w/cold air intake, OBA, 4.5" lift, Woody CV shaft and Tattons in front, 4.10 gears - lunchbox in front, Truetrac in the back, twin-sticked, blower upgrade for running topless, trying to keep it simple.

It's just a Jeep, and if you don't wheel it once in a while, it's not even that.
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Unread 09-12-2008, 07:43 AM   #12
GRI
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I had this setup, but I wound up taking the holley 390 off and putting a motorcraft 2150 on it and the low end was ten times better and climbing on inclines were were nicer. it didnt sputter like the holley.
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Unread 11-23-2008, 09:49 AM   #13
clintb
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I bought jeep with the Clifford and 40 (1980). How did you get the right Motorcraft carb. Our junk yards have dumped those so are hard to find unless thru parts place and not sure what vehicle to order against?
Thanks in advance for the info:
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Unread 11-23-2008, 09:57 AM   #14
coldwater
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I run the intake and 6>1 header with a webber carb and Jacobs electronics. No engine work at all has been done over stock. The gain in low end grunt was amazing, as well, it starts instantly, runs like a watch, and the fuel mileage took a huge jump. I'm a big fan.
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Unread 06-18-2009, 06:27 PM   #15
BigMac72
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Just rebuilding my 258. Using a Clifford cam 264, intake and header. I took the head in to be redecked and while it was there had it ported for $200. I thought that the porting way to go was easier with almost the same results. I have a hei distributor and centech wiring so when the arp head bolts get here in the mail, I'll be anxious to fire it up.
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