Good 400+ HP 360 build

I would certainly NOT go backwards on a cam!

I'll probably go with a 268 cam then, it would probably work pretty good, but I don't think I want to go any bigger then that, and I would be pretty happy with 350, nothing wrong with that. And I don't want to bore it out because I would like to keep this build cheap, but if I have to because of wear or something I'll bore out the block. And I'll look into a good converter also.

I got the impression that the "400hp" figure is more of a cruise night target for you DV. The 268 cams will be very fun pacakges without the added stuff (machine labor, springs, losing power brakes) to support something larger. Witha good piston and solid performance machining (especially in terms of the cylinder heads and wall finish) it should get close to the 400hp level and be a blast. As for a convertor - best bet is to contact a convertor company and tell them what you have and what you want to do. IMO - do not tell them you want to drag race it as a top priority or you will give up some driveability for little on the track. My order of recommendation - Ultimate Convertor Concepts, PTC, Dynamic (in NC). if you want a cheaper one - the Mancini 2200-2500 are a decent part for little cash & make sure you get the right flex plate for you package.

My 318 made 352hp @5700 and 367ft/lb of torque @ 4400

Performer RPM intake.
650 AVS carb.
Stock 340 915 J heads 2.02"/1.6" ferrea valves
Thumpr hyd flat tappet cam
10.2:1 compression
1-3/4 headers 30" in length

Stock stall converter was a PITA, likes the 3000 much better.

YY1 said:

I wish that Hot Rod mag article had gone a head and tested the cam (or one that didn't require machining) with out the high dollar heads and rocker assemblies.

I used to know what the diff was between the 300 and 380 HP versions of that crate motor. Were the pistons different?

Click to expand...

the 300 horse is a stock magnum with a carb and headers, which actually came out to 320

the 380 has a m1 single plane and a hyd flat tappet 292 @ 501

I have read that the 380's will pull close to 400 hp on the dyno

For the 268 I've read that you can run the stock converter, because that's just one less thing that I would have to buy. What would happen if I used the 268 and my stock converter? Or are converters alot cheaper then I though they are?

Just have your stock converter sent off and tweaked for a little higher stall speed.

I personally wouldn't run ANY aftermarket cam without matching the torque converter to suit.

What would happen? The engine would start, you'd select "Drive", and it would go into gear and pull away when you hit the gas. The trick to matching a convertor to an engine/driveline/car package is to keep it low enough to be "locked" in drive at cruising speeds, but lose enough to slip a little in low gear and low rpm to work with the gearing and weight and allow the engine to get up into the torque band earlier. A stock convertor is inefficient in high gear and tight low down. The factory high stall units were much better - that's what you find in 340, 383HP, and 440HP cars. They are smaller diameter than the low stall units. The 268 cam's torque is right off idle - so you don't have to have that lose bit at low rpm with them. They will be quicker if you have a little stall to the convertor. But you don't have to have it which is why I recommended it.

I'll add one of my customers has one of the Mancini Racing units in his car. It makes 470hp and gets 17mpg with a 2200 stall. Also runs 12.80s in a 3800lbs car. Something similar now is this:
https://www.coperacingtrans.com/pro...d=245&osCsid=b9a7addfe8a5e8dbcdd0e59f06b9117a

Made by PTC - sold by John Cope. Great peice for $280.

That is a good bang,for the buck.(CRT converter).