Thread: Rebuild or Replace? need advice!

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Thanks to this forum, I now have a pretty good idea of what I've got in terms of a drivetrain, now I need some help deciding whether to rebuild it, or replace it. The car is a '63 Chevy II 2-door hardtop. A previous owner replaced the original 6 with a 30 over 350 small block, but kept the Powerglide. The engine is no great shakes, being a 72 or 73 truck engine with 76cc heads, Torker 2 intake, and Carter AFB 750 carb, and stock exhaust manifolds. My goals are pretty modest, to make 320-350hp, and to run cool in city traffic.

Of course, money is tight. Should I tear it down and take it to a machine shop, then re-assemble it with a kit, or will I be better off with the low-end (290hp) GM crate motor?

With my existing block and heads, will I be able to reach my 320hp goal with headers, and a different cam and intake?

Should I keep the powerglide, or swap in a th350? All input is appreciated, cause this is all new to me. Thanks!

loner, here are 109 dyno-tested SBC combinations. Look through here and see what suits your fancy, then price the parts to do the build and add machine work.
http://www.ryanscarpage.50megs.com/combos1.html

As far as the trans, 2,800 lbs is considered the weight limit in drag racing before you should swap out the 'glide for a TH350 or TH400.

Thanks TI, especially for your input on the trans.

That page is a good resource, and I already have it bookmarked. I guess I was wondering if I could reach my goals with the block and heads I have. Any thoughts on that?

the t-350 will be lighter and can be built just as strong. also i know a good engine combo for a nova.

Originally posted by gassersrule_196
i know a good engine combo for a nova.

Yeah, but 283 blocks are a little harder to come by

Scooter, don't you have a 3" crank you can let him have?

loner, the heads are gonna be the problem. You'll have to spend a wad of money to crutch 'em up with other parts to try and get any power out of the motor. the best part of 'em is the 76 cc chambers. You'll need those with flat-tops to keep c.r. down to a level to use with pump gas.

there's just no way around it, horsepower costs money.

Here's a set of World Products S/R Torquer heads on ebay. Big valves, small 170 cc intake runners for high velocity of the intake charge, 76 cc chambers for a reasonable c.r. With these heads, stock 4-eyebrow pistons, zero deck and a 0.039" gasket, you'd be at 9.26:1
http://cgi.ebay.com/ebaymotors/ws/eB...sPageName=WDVW
This guy has 99.4% positive feedback, so chances are he's ok to deal with. I'm not saying you should buy these particular heads, I'm just showing you that there are affordable heads out there.

:

The good Doc... loves those peanut motors too...

I have about 10 complete 283's lying around and maybe 4- 327's

just can't beat "old" iron

Originally posted by techinspector1
Scooter, don't you have a 3" crank you can let him have?

loner, the heads are gonna be the problem. You'll have to spend a wad of money to crutch 'em up with other parts to try and get any power out of the motor. the best part of 'em is the 76 cc chambers. You'll need those with flat-tops to keep c.r. down to a level to use with pump gas.

there's just no way around it, horsepower costs money.

Here's a set of World Products S/R Torquer heads on ebay. Big valves, small 170 cc intake runners for high velocity of the intake charge, 76 cc chambers for a reasonable c.r. With these heads, stock 4-eyebrow pistons, zero deck and a 0.039" gasket, you'd be at 9.26:1
http://cgi.ebay.com/ebaymotors/ws/eB...sPageName=WDVW
This guy has 99.4% positive feedback, so chances are he's ok to deal with. I'm not saying you should buy these particular heads, I'm just showing you that there are affordable heads out there.

Wow, he even goes to the effort of finding me a local auction! You guys are great. Ok, here is the level of my ignorance: Is it not possible then to put a different sized set of heads (like 64cc) on this block? I have no idea.

Sure, loner, you can bolt any SBC head on the motor that you want to, but if this is gonna be a street motor to be operated on pump gas, you want to keep the static compression ratio low enough so that the motor won't detonate (ping) on pump gas. Of course you can also use a cam with a later intake valve closing event to bleed off some of the compression, but then you also have moved the operating range of the engine up higher in the rpm range and away from streetability. 9.0:1 is a generally accepted limit for iron heads, although I've seen fellows run as high as 11.0:1 with a good tight squish. Personally, I'd shoot for somewhere between 9.0:1 and 9.5:1 with a 0.035" to 0.040" squish. That's the dimension between the top of the piston crown and the cylinder head at TDC.

If you use heads with a smaller chamber such as the 64 cc units, you'll also have to use dished pistons to keep the c.r. relatively low. For instance, a 0.030" overbored 350 with 64cc heads, stock-type flattops, zero deck and 0.039" gasket, will yield a c.r. of 10.56:1. You'll want to match the cam to the c.r., so you would install a more agressive grind and move the effective power higher up and away from streetability. Now of course you could do that and get away with it by running a converter with a higher stall, but there are other things to consider too, like manifold vacuum to operate brakes and such. The more cam you run, the lower the vacuum.

For a good solid street motor, keep the c.r. around 9.0:1 and use a mild cam.

So, your choice is either large combustion chambers with flat-tops or small combustion chambers with dished pistons.

If you want to bone up on c.r., see this paper I wrote:
http://streetmachinesoftablerock.com...opic.php?t=124

To bone up on cams, see this one:
http://streetmachinesoftablerock.com...topic.php?t=78

looking for a way to make a shaker hood work on a torker intake manifold

Originally posted by dr_bowtie
The good Doc... loves those peanut motors too...

I have about 10 complete 283's lying around and maybe 4- 327's

just can't beat "old" iron

well i want one LOL

Originally posted by techinspector1
Sure, loner, you can bolt any SBC head on the motor that you want to, but if this is gonna be a street motor to be operated on pump gas, you want to keep the static compression ratio low enough so that the motor won't detonate (ping) on pump gas...

Thanks again, I will read and learn. I also intend to pick up the Dave Vizard books on CSBs, since they seem to be well regarded. Any other book or website recommendations, just let me know.