Have a 4 bolt mark IV sitting in the garage. Last year took my 327ci out of a '67 Impala SS (Big heavy Chey) with TH400 trany. Planning on running 67 rect ports 100cc closed chamber heads with Vette tripower auto set up off 68 vette. What would be the best bottom end CR, build and soild roller cam setup for this build, and what rear end setup would work best for the street ? Want mean street machine if possible.......Any suggestions would also be helpful Such as sell these heads and go with aftermarket. I am sure the 67 heaads are worth $$ to some one who needs them.

In 67 the Impala was going to be offered with the tripower 427 setup but GM took it off last sencond. This is why the '67 427 had the 3 chrome parts were on the hood.

For starters, what will the car be used for? Also, what are the casting nums on those heads? Everything I was familiar with was more like 107cc or so. Were they milled? Most all of those rect. port heads are pretty big in the intake runner volume, resulting in a 'softer' low end...not terrible, but they wont pull like an oval port engine. They are more suited to higher rpm use. Im in the process now of taking a rect. port set off my 505 and going with worked oval ports. Try a search on this topic if you havn't already done so, there is a whole lot of info here on 496 engines. Common combo is a forged or even cast crank (cast is good to at least 600 HP) , forged rods and pistons, and heads are all over the place...lots of guys use GM heads, usually with bigger valves and some port work. There are also a lot of aftermarket heads, some aluminum. Go for no more than 10/1 if you want to stay with 93 octane. Lots of solid rollers on the street too, most are in the range of 250/260 @ .050, some smaller, some bigger. Again, it depends on what you want to do with the car.

I may be wrong but most tripower intake setups quit making power aroung 5500 rpm.. I would not use a solid roller for a 496 that has tripower ! NOW if your running a single plane and 7000 rpm i would consider a solid roller .
I think you would be better off with a mild hyd roller..

Hydralic roller cams are a waste of time, if you are using a grind that is mild enough to not rev past 60-6500, then a flat tappet cam can be ground just as aggressive, and ALOT less expensive. when selecting a grind that has ramps designed for over 6500 RPM, then NOTHING compares to a solid roller. my .02
Barrett

Jus my $.03 rergarding the above stament referring to HR cams - try telling that to some of they guys here in the 9's and 10's that HR cams are a waste.

And in a street car, a hydraulic roller achieving the same power will have much better driveabilty than a flat tappet cam. I agree you can achieve similiar power levels, but they will be two different animals.

...and screw a bunch of flattened lobes, give me a roller cam, thank you very much. The consequences of a single flattened lobe will cost more than the switch to a roller setup - pull and disassemble the engine, fresh rings and hone, all new bearings, etc.

Gary,

Couldn't agree more!