Vega

So im new here and posted some of this in my introduction post but i feel the main questions are better suited for a thread here, especially if im going to be keeping you guys posted on this and using your suggestions and guidence as i go.

I just recently got a 72' 455 that ive torn down to bare block. It had spun a main bearing and most likely needs turned .10 over, no big deal really. The motor looked like hell when i got it honestly (got it for $100 from a guy who was just tired of looking at it). I got it home and power washed it and wha-la! there's still a lot of blue on that thing after all, haha, night and day difference. Well now i know it has Ga heads (me and the guy selling it both thought it had G heads if that tells you just how much grease was stalagtiting off this thing). Found out from the valve cover notches and small non-Toro oil pan that it was from a 72' Cutlass or 442 (which makes me excited because thats exactly what i want to do with it, use it for a 71'/72' 442 project)

At the moment my plan of attack is such:
Prep the block,
Machine the crank (including drilling for use with a 4-speed),
Get the heads re-done (im not picky about the Ga heads, i wont cry over wanting C heads, i have 455 cubes of motor and 2 heads that fit it that arent J "junk" heads so im happy),
Get flat top pistons re-using the stock rods,
Toss in a hefty cam (right now im looking at the Comp Cam XE274, any suggestions on how this cam performs? Maybe you know of one that id like better? Im looking for a wicked idle in a 4-speed street car, might see the strip on a whim eventually but mainly street).

Any suggestions would be appreciated, this is my first rebuild although im co-rebuilding with my friend who rebuilt his friend's 72' Chevelle's 454 so at least there is some GM big block knowledge here
Also im planning to do this on a budget (lots of ebaying, lots of re-using parts if possible, i know all 455 bottom ends are damn well indestructible unless you set it on railroad tracks or fire Panzer shells at it so im not worried about that at all, this is all about top-side compression and performance)

Vega

Forgot to mention, this is a virgin block with stock pistons, the guts of this thing look amazing for a 5-year old car let alone 40! The cylinders look great, contemplating getting stock sized flat tops or going 30-over just for the added "umph". Not sure if the heads are large valve or not, can this be measured with a tape measure?

I can post pics if anyone is interested, im very pleased with what i have now that i can see and inspect all of the internals. I could definatly turn around and part this motor out for $400, an easy $300 profit, but i hate people who take advantage of muscle car stuff like that (i know a guy who bought a 72' Nova for $13k just to re-sell it for $15k, i kinda wanna take a hot-glue gun to his eyes LOL) not to mention i love having a good foundation to build from

So on with the build!

Rickman48

If the main web on the spun main is blue, you've a junk block, as it's overheated and warped!
If not, it must be line bored to regain a machined surface.
Might as well have it 'squared' too - mill the cylinder bank surface parallel to the crank bores - have seen this measurement off as much as .020 from one end to the other!
This equalizes piston to deck measurements, hence combustion chamber volume.

cutlassefi

You could still have heads that are unequal but yes this helps.

An Erson TQ50 cam would be great in that 455 with the G heads (yes you can check the valve sizes with a ruler) and 9.5:1 or better. Cam specs are 228/235 @ .050 on a 110 with .504 lift on both intake and exhaust. Very valvetrain friendly especially if it's stock or near stock.

Sounds like a fun build, good luck!

dc2x4drvr

For a budget rebuild your piston choices are probably limited to stock cast, TRW forged, or hypereutectic, nice flat tops are expensive. I run the XE274 Comp cam, and it's on the edge vacuum wise if you're running power brakes, the idle isn't wicked at all..

cutlassefi

A little FYI, that's because of the smallish exhaust lobe.

I'll say it again, as long as you have ample compression, stock heads do better with more of the seat time, not the fast ramp stuff. I'm sure yours runs good but that doesn't mean it wouldn't run better with something else.

Jmo.

Oldsmaniac

A big nasty sounding cam at idle will turn an engine into a slug without other mods such as steep rear end gear, high stall converter and you will loose vacuum for things such as power brakes. Rods should always be reconditioned and checked in a rebuild. Bores cannot be assumed good without measurement. Low cost usually means low performance and longevity. Yes with a spun main the block needs to be checked good before the crank is bolted back in.

cutlassefi

Just an fyi as well, you can take a cam with a smallish intake lobe for good vacuum and pair it with an exhaust lobe with significantly more off the seat and get a good sound without much of a compromise.

Vega

Thanks guys, lots of good advice. Yeah ive actually heard a lot about the Erson cams lately and pretty impressed with what ive heard and seen, for me they just came out of the blue and started blowing holes in the competition haha, thats pretty awsome. As far as cam goes im going to be running a manual transmission so stall converter isnt an issue, and when i get the heads re-done im gonna update a lot of it

I'll definatly check the block and have it double checked when i take it in for the prepping and such (dont wanna prep a block that is junked out anyways).
There is a pretty decent grove in the crank about enough to catch a fingernail so i'll have to get that worked out.
As far as the pistons go ive been looking into Speed Pros, I will definatly get the rods checked and all just to be sure.

Honestly im not planning to go too far from stock, at the moment it might be a bit more than "budget build" but put simply im just looking to up the compression and modernize the cam. You know actually (i have no idea why i didnt consider this earlier, i must be far-sighted LOL) i could probly just ebay a set of reconditioned stock 69 or 70 pistons with better compression right? and then just focus everything on prep work, heads, and cam?


PS: Rickman48, i was considering getting the block decked, which would give me an excuse to square it right? haha

Vega

Oh hey one more thing. There is an E85 station near me and i was toying with the idea of converting this motor to E85 for better octane, maybe boost the compression more to take full advantage of it.

I know a LOT about E85, i know there's a lot of propaganda that isnt true out there for it, im not looking for pros and cons cause ive done all my research already, im just wondering if anyone here has done it (just for sake of staving off an E85 witch hunt speech just assume im talking about higher octane gasoline LOL) how much compression can stock heads (Ga heads) take? Would i have to go up to Edelbrocks to take full advantage of this?