R4B VS, PERFORMER

[JERSEYJOE]

I know there are a lot of opinions but I am looking for some fact. Talking about a street only J-20 truck used for towing and no low speed off roading, has a stock 360, stock crap cam and exhaust. Which would work better the R4B or the Performer all other things being equal? I am planning on swapping the heads for the early 291 heads to get the compression up around 9:1 and replacing the cam , and installing the Edelbrock TES exhaust later on ( Spring 08 )

[J4GRAND]

Performer. Better low end than the R4B which is more for high speed/RPM applications.

[tufcj]

I agree on the Performer. The R4B is more for mid range performance. You won't see the total performance gain until you do the intake, cam AND exhaust (think duals with an "H" pipe). The bump in compression will help HP some but the 291 heads don't flow as well as the later ones, so torque may drop. I don't know that the head swap will gain anything in the towing arena.

For towing, do what you can to increase torque, don't worry about HP. Torque gets you off the line, HP makes MPH.

Bob
tufcj

[JERSEYJOE]

HOW MUCH BETTER IS THE PERFORMER THAN THE STOCK AMC 4 BBL INTAKE? I ASSUME THE PERFORMER HAS SMALLER RUNNERS FOR MORE AIR FLOW VELOCITY AND THEREFORE MORE TORQUE.

[fifesjeep]

Have You tried to Google it? I found a lot of info, Flow rates (Bench testing) etc on the web.... I'm sure you'll find the answers you're looking for. :razz: I also agree that the performer is better... It's better enough to spend the extra change to get one, Unless you like pinching pennies then you might as-well keep what you got. You could always do the shade-tree way and move up in Rocker Ratio's... That would make that stock cam (Which isn't bad for a stocker) have a lot more torque on the lower half... A couple mods on the heads, possibly longer/shorter pushrods and that stocker will be plenty. 111!!!

[JERSEYJOE]

I am lucky enough to have all types of AMC manifolds from Performer to Torker, to R4B, stocker. and even a factory cross ram.. I was going to start with a baseline performance and mileage test on the stock 360 2 bbl and go from there. I am a little too lazy this time of the year to do a cam swap so it will wait until Spring.

[jeepsr4ever]

Joe I would love to see a comparison!!!

[rollen dean montoya]

mongo would too. just might be aquiring a fsj cherokee.
i believe it might have either a 401 or a 360 . still trying to contact the owner

[SHARPMACHINE]

I am with you all on the intake and cam questions.

I run a stock 360 in my jeep and want to do some upgrades.

Planning on a cam, intake and 4-barrel. I already have a facory intake, but am wondering if I should try to find/trade for an aftermarket intake??? I am also wondering how much my single 2.5" exhaust with a flowmaster is holding me back versus duals??

Anyway, I will read on

thanks

[76-cj7]

If you're looking for torque, wouldn't the SP2P Edelbrock intake be a good choice b/c of its small runners??

[jeepsr4ever]

The performer intake works extremely well for low and midrange over the stock 4bbl intake. And it weighs some 40lbs less.