head fitment

[bcuda452]

Ok guys, im sure this has been covered a thousand times but i need to ask anyway, im looking at a 67 273 for my 67 Barracuda, it is a short block 4 barrel motor, my question is i have a set of J heads that i would like to put on this motor, ive heard rumors of "notching" the block? Is this correct for one,and what other mods do i need to do? The cam selected is a 509/292 solid, if that makes any difference............

thanks for the help

Doug

 

[70aarcuda]

dont know exactly what bore size your is...or whether you got 2.02 intake or 1.88...but do the math...

add the valves together plus .030 between the valves...and ???

big problem...is the 70 cc head ...will kill the compression...and 292 duration will make the engine the a big dog......

 

[RustyRatRod]

Huge cam. Tiny engine. Big problem.

 

[JBurch]

Maybe not the most practical match up of parts, but it's what you want to do.........

Yes to needing to notch the bores, just don't cut down into the path of ring travel, cut the heads down to the smallest chamber you can to minimize your compression loss, you don't have alot to start with.

With that much cam, I hope it's a 4spd car, or loose converter and deep gears, rpm is gonna be a necessity, not a luxury.

For reference, get a re-print of "Darn Dart", from "Mopar Action", at this point probably 20 years ago or more. It chronicles a 67 273 Dart that went 10's in the quarter mile.

 

[bcuda452]

k thanks guys, i guess a different plan will have to be thought of.......

 

[CultClassik]

Honestly unless you're going for pure nostalgia, there's no reason I can think of to use a 273. You can get a 318 so cheap, and with it, the same crank but 45 more cubes. Even with stock low compression pistons, it's not too bad with a decent set of heads (I used those '67 273 heads on mine!) and a reasonable cam and it's a fun car, even if you're not going to beat everybody at the strip.

 

[66fs]

I've run 72 340 J heads on a + .040 273 commando engine. If 1.88 intake valves, they should be OK but I mocked up the engine to check everything. Used offset dowels to center the chambers on the cylinders. Milled the heads to NHRA minimum, .040 block side and .038 intake side, ran Fel-Pro gaskets. Ran a stock 340 cam, lifters,valve springs, 71 340 intake and TQ. Ran great! Was in a 64 Barracuda, 4 speed had plenty of power everywhere. The Racing manuals said to notch the block for 2.02 intakes. You can do it just check everything so nothing goes bump, and remember everything has a tolerance.

 

[roccodart440]

dont know exactly what bore size your is...or whether you got 2.02 intake or 1.88...but do the math... add the valves together plus .030 between the valves...and ???

It's not that simple because the valves don't come straight down into the bore.

Huge cam. Tiny engine. Big problem.

That huge came. Tiny engine. Big Problem.

 

[70aarcuda]

small block mopar valves are on centerline of the bore......