Anyone here try installing the afore mentioned manifold on a carbed 300? I can get one off of an 88 for $10, and was wondering if it is worthwhile, as, I am in the process of swapping engines in my truck, and I would love to be able to run true duals on it, as the engine I am installing is up to performance mods(84 300 with 70,000 miles) and I can't see myself buying a header if the newer exhaust manifold is just as good. Also, if anyone has done this, how does it sound, if I do go with duals, I'm going to be using 2½" pipes with 31" Cherrybombs, exiting in the stock locations, behind the rear wheels of my 82 F100 Flareside(I know it's a little newer than this board covers, but I can't get much help on the 80-96 board.)
Evan MacDonald

 

evan I did this swap on an 86 f150 with 300. the hard part is getting the exhaust gasket which is for integrated head to stay put while lining the intake and exhaust for bolt instalation. I recomend using tacky spray adhesive on head and gasket and when super stickey apply. Start in middle of intake,you know the hardest one ,and work your way out.As for sound it will sound like a 300 with headers.Personally I would not go cherry bombs because even with mufflers and duals it will be noticable.

 

I guess I'll pick up the manifold tomorrow, then I'll wrestle with the gasket, which one should I use, one for the new manifold, or the one that is on the engine? As for the noise, I'll not be deterred from running cherry bombs by it, but, I just dug out another complete exhaust to fit the truck that I can make fit the left side, so It will have stock sized pipes(21/4" I believe) stock mufflers, blown out cats(adds a nice ring to the exhaust) which will eventually be supported on the other end by a 4 barrel Offenhauser manifold and 390 cfm Holley. Now to put an ARB airlocker in the 9" so that I will be able to get up the road to my hunting camp, alot of good a 164 mph top speed(SROD and 3.00's) does me when I can't get traction....
Evan MacDonald

 

If you plan on keeping that rear end you might want to consider getting a real 4 speed so you can get it started from a dead stop.

Trail Rider

 

I`m doing similar mods to the 240 in my `69 Econoline.I have the Offy 4bbl intake,but i`m using a 2bbl adapter and 350cfm Holley 2bbl carb instead of the 4bbl since i really don`t need a 4bbl on it.As for using cherry bombs on it,i have one on mine now and it does not sound good at all with the six.Consider using the Purple Hornies that Jeg`s sells,they seem to sound great.Thats what i`m going to use when i add the intake,split header,etc.

 

I have put the exhaust together, using the duals and glasspacks, I kinda like the sound of mine now, it sounds like a 353 Detroit 2 stroke deisel to me, sure, it doesn't sound like a V8, but it confuses the hell out of my neighbors(espically the nosy ones.) I have decided to keep the 3.00's in the rear end, but, I replaced the transmission Saturday, the SROD started to act up on Thursday, so I got a real 4 speed truck tranny, a NP 435, my only beef is with the @$$wipe who made off with the shifter.
Evan MacDonald

 

I would recomend at least a 390cfm 4bbl for a street truck. I have a '86 Mustang 2.3 with a Offy dual port 4bbl intake (yes they made it for the 2.3 also) and I use to run a 350cfm 2bbl, had nice torque and everything, but my milage was in the low teens (bad for a 2.3), then a friend gave me a 390 cfm Holley 4bbl that needed a rebuild, I rebuilt it and put that on, WOW. I have alot more low end grunt because of the small (195 cfm) primarys and I get milage in the high 20s-low 30s now! If I kick in the secondarys (the other 195cfms) I get a nice kick in the pants and it doesn't affect milage to much.

If you don't have it over half way down all the way. You WILL get better milage and more torque with a small 4bbl with vacume secondarys!