Hey guys, I'm getting to work on my build and would like to get some feedback on my ideas as to where I'm going with my engine. I want some advice from anyone that might have some experience with Vortec heads on older SBC motors. I'm building a strictly street car, just want something that will idle nicely, but with a little attitude. I want to be able to drive this thing, and be comfortable doing it, but also light them up a little bit at the red lights, or when one of those god forsaken fart boxes are next to me.
Story on the car/current power: I picked up the car back in October, containing a god awful 250 inline 6 that put more oil out the tail pipes than in the pan, but with 396 badges on the side.......... I checked vin and found that I have what used to be a 396 car, with a Turbo 400 behind it. The Trans will go back in the car, but the 250 is beyond its last day, and thus the car is now minus front clip and ready to get that turd outa there. Don't get me wrong, the 250 had its application, but it didn't belong in an Impala, maybe a Vega? (Had one of them too
Story on this motor goes like this... I found a screamin deal on a complete (minus carb) 350 motor on Craigslist, paid less than $100 for it. It's a '72 4 bolt block, 010 casting, with same era heads (don't remember casting number on the head). The previous owner said he had it in his '68 Camaro up until about 5 years ago when he did an LS1 swap. The motor has been sitting since. He said that it used about a half quart to quart of oil per 3k oil change. I figured I'd be able to throw some new rings, bearings, and gaskets in and have a decent running streeter until I can stomach the $$ for an LS swap. Well things change...
Got her stripped down a few days ago and found grooves around several of the crank journals. Bearings were all in place, so nothing spun, but the grooves on 2 of the journals were noticeable from 10 feet away, and easily caught the fingernail. So now I'm looking at either a return on the crank, or a new crank altogether. You see where I'm going with this now????? I figured it'd be at least $100-150 for GOOD machine work on the crank, or I can buy a Scat 383 crank for $200-250.
So now I'm thinking a 383 sounds like a good idea. Lets take this one step further, I have a buddy that has a set of 062 casting Vortec heads that he wants to get rid of, and he happens to want the truck heads and intake that I have. SO, since I can get the heads for a decent price, I'm considering going this route. This is where things get interesting. There isn't a TON of info on doing a Vortec 383 SBC, and I'm wondering if maybe thats for good reason.
With a 350 block, and the 64cc Vortec heads, you can expect to get 20-30 hp pretty easily out of the swap from a stock head, but will that small of a chamber choke out the longer stroked 383? I know that the Vortec heads flow faster than other heads, so maybe that would help SOME, but most 383 builds I see are using an 80-90+ cc head. Can anyone shed some light on this for me?
Also, this smaller chamber, combined with longer stroke, SHOULD give me A LOT more compression. I'm no pro, and I don't pretend to be, but based on the calculator I used, with a 4.03 bore, 3.75 stroke, 64cc chamber, .039 gasket and a flat top piston I'd be around 11.5-12.0:1... Did I mention that I like pump gas?
My question here is, first does that sound somewhat accurate, second, has anyone done a swap like this that might know approximate CR, and third would dished pistons drop it enough to get me in that 10-ish range?
Basically, I just want some opinions on whether I'm just trying something new that others haven't really thought of or wanted to try (Vortec 383), or is it because the Vortec heads just don't work well with the 383 setup?
NOTICE - I'm doing this on a budget, so I don't want the answers like "just go spend the $1200 for built Dart heads and be done with it"
I'm not building a strip car, and the thought of building a junkyard freak show sounds pretty damn cool to me. Sorry for the novel, just wanted all the info out there.