Thinking about bolting a CJ intake on my dads 429 w/d0ve heads. I realize the intake runners will need port matched. My question is will we see any improvement? We pull this truck in a street class a need more rpm's. It has a Lunati bracket master II cam,a 750 double pumper and that's about it.

 

I ran one for a long time on my motor with mis matched ports. I could tell it helped a little bit. Be sure and use CJ gaskets or it won't seal. What kind of RPM's or you turning on the track?

Dennis
1999 F-350 Powerstroke
1977 Highboy 429 4-speed 35"s
1972 Ranger on a 1978 F-250 4x4
frame 466 Pulling Truck

 

Right now it turns about 53-5700. We would like to see it in the 6-6500 rpm range. It will probably take more than just an intake I'm sure.

 

If you still have stock rod bolts in that 429, you're on borrowed time spinning it any higher than 5500. I wouldn't be revving that high with stock rods anyway, they are not the beefiest.

 

I've heard of people running the CJ heads with port mismatch, and getting good results... But, it is very easy to blend the ports to the CJ gasket.
Mark

 

Those RPM's are pretty good for stock intake and a 750 carb. I went from a 750 to a 950 and it gained alot of power and about 5-800 more rpm's. If you change the intake and get a bigger carb you might be able to do what you want. What kind of exhaust are you running? As far as porting the heads to match the intake, it takes several hours with a grinder. I have done two sets. On the subject of stock rods. I have been running stock truck rods in my motor for six years with stock bolt and turn it 6-6500 everytime it goes down the track and have never had any problems. This year I plan on turning 7-7500 so I did put a set of ARP bolts in them.

Dennis
1999 F-350 Powerstroke
1977 Highboy 429 4-speed 35"s
1972 Ranger on a 1978 F-250 4x4
frame 466 Pulling Truck

 

Those RPM's are pretty good for stock intake and a 750 carb. I went from a 750 to a 950 and it gained alot of power and about 5-800 more rpm's. If you change the intake and get a bigger carb you might be able to do what you want. What kind of exhaust are you running? As far as porting the heads to match the intake, it takes several hours with a grinder. I have done two sets. On the subject of stock rods. I have been running stock truck rods in my motor for six years with stock bolt and turn it 6-6500 everytime it goes down the track and have never had any problems. This year I plan on turning 7-7500 so I did put a set of ARP bolts in them.

Dennis
1999 F-350 Powerstroke
1977 Highboy 429 4-speed 35"s
1972 Ranger on a 1978 F-250 4x4
frame 466 Pulling Truck

 

Those RPM's are pretty good for stock intake and a 750 carb. I went from a 750 to a 950 and it gained alot of power and about 5-800 more rpm's. If you change the intake and get a bigger carb you might be able to do what you want. What kind of exhaust are you running? As far as porting the heads to match the intake, it takes several hours with a grinder. I have done two sets. On the subject of stock rods. I have been running stock truck rods in my motor for six years with stock bolt and turn it 6-6500 everytime it goes down the track and have never had any problems. This year I plan on turning 7-7500 so I did put a set of ARP bolts in them.

Dennis
1999 F-350 Powerstroke
1977 Highboy 429 4-speed 35"s
1972 Ranger on a 1978 F-250 4x4
frame 466 Pulling Truck

 

Sorry about the triple reply. I was having trouble sending.

Dennis
1999 F-350 Powerstroke
1977 Highboy 429 4-speed 35"s
1972 Ranger on a 1978 F-250 4x4
frame 466 Pulling Truck

 

Thanks for the info. We're going to go ahead and put it on and port match the heads. Dad's truck is still running through stock exhaust manifolds with 2 1/2" exhaust. I couldn't believe those rpms either! Headers are coming soon.

 

I would keep the 2 1/2 inch dual exhaust. That is a good size for a motor like that. I run 2 1/4, and it works well, so 2 1/2 will only be better, especially with the headers. Stick with 1 1/2 inch primaries, or not much bigger, or you can over scavenge the heads with too slippery an exhaust path, and you will need more air in.
Mark

 

If you can run fenderwell exit headers I would recommend a set of heddmans mentioned in an other thread and 3" exhaust. That will make a huge difference also.

Dennis
1999 F-350 Powerstroke
1977 Highboy 429 4-speed 35"s
1972 Ranger on a 1978 F-250 4x4
frame 466 Pulling Truck

 

Will fenderwell headers pass inspection in street class???
Mark

 

hybridf250! What are you running for a transmission? What ring and pinion? (gear ratio). Street Stock pulling classes vary in different parts of the country, as do sleds that are used at truck pulling events. In my part of the country (WI) a good rule of thumb is to try and run about 26-27 for a final. Example, transfer case ratio low range (1.96)x transmission (np435) ratio 2nd gear (3.31)x ring and pinion (4.10) =26.5. If you try to run to tall of a final you can't get on top of the motor. I'm not saying that you may or may not have enough motor, but you have to look at everything, and final ratio is very important. As for CJ rods, have them resized, stress relieved and install ARP bolts in them, (as greenhighboy said he's going to do) and with everything right you can spin them 7200-7500, done it for years and never had a rod peek out the side, but they won't last forever, so pick a time frame or number of hooks, then retire them and start over. We ran aluminum rods 105-115 hooks and then hung them on the wall.

 

I wouldn't try for anymore RPMs without paying some attention to the valve train. DOVE rail rocker arms shouldn't be spun much more than 5000rpm without guideplates and hardened pushrods. As an example, the CJ/SCJs were rated at 5600/5800rpm with 5/16" hardened pushrods/guideplates, cam lift of .509 with intake/exhaust ports that dwarf the DOVEs and they still bent pushrods. 6000-6500rpm will call for roller rockers, 3/8" pushrods and guideplates if you want the most out of the engine and any safety factor.

6000/6500 will take a cam with durations of at least 230 degrees @ .050, but stock DOVE heads will limit your effective lift to about .500 as the exhaust port flows a maximum of 135cfm, period. You'll need to port the exhaust to where it'll flow at least 175-185cfm to see 6500rpm on a consistant basis. People run big cams with stock heads, but all they're doing is putting up with a radical idle for no actual increase in performance. If you're going to get serious and are limited to iron heads, go to a set of PI or CJ heads now.

Stock rods are ok to 5500rpm, plenty of people run them higher than that, but when I put several thousand dollars into an engine I prefer to use at least DOOE rods with ARP bolts. The extra $250 is cheap insurance.

Exhaust is a big issue on the 385. Full tube headers with 3" exhaust off the collectors will pay for itself.

As others have said, go to at least an 850cfm carb, more if you make the modifications to run at 6500rpm.