72 LS5

Or the rocker nut backed off. Unfortunately, if the engine was run with slop in the valvetrain, damage to the cam lobe can result. I think the cause is the oil. You HAVE to run an oil rich in zinc in a flat tappet motor or the cam will fail . It happened to me. I reset the lash, started it up and noticed that rocker was only going up and down 1/2 the distance as the others. Cam went flat.......and I was running regular Castrol 10/30 which has like no zinc.

Curious why you had to relash, unless its a solid cam.

I have 3.31s and love them. BUT, on the highway I cruise at 3000-3200 rpms and I'm in the slow lane doing just shy of 70 mph, getting past by campers - everybody does 75++ around here. I have 255s 60 15s, btw. I wouldn't want to go on any long trips with that gear and no overdrive, but its great for winding backroads, around town, and a quick blast on the highway. Running a 28 inch tire certainly would give you another 4-5 mph on the highway. I'm keeping my 3.31s.

HA!

If you do a combo of city/highway, you may want to consider a 3.08 gear. I put that in my 85 Monte with a 355 and turbo 350 trans with a mild converter. You may not be in the fast lane on the interstate with 3.08, but you can keep up with traffic w/o going over 3k rpms, and you'll still have some off the line dig. Plus, with that ratio, you can really tweak it with tire size if you aren't 100% happy with the results. 2.56s are tall gears, but when I found out the original gear in my 85 was a 2.29, I almost fell off my chair. Before I changed to the 3.08, I would only use 2 gears down the track - it sounded like a powerglide car!

I've found the staggered jet topic very interesting, but like you noted, it was recommended by Chevy for the open plenum, dual plane manifold only. I was going to do this myself, but my Eddy RPM has a notched divider, but its not open. Those GM dual planes with the open dividers were installed in high rpm solid lifter motors. Here is another guys resuts: http://www.chevelles.com/forums/showthread.php?t=182244

That mouse will scream!

I still haven't gotten my new engine fired up, but I went roller this time so its supposedly not an issue. Regardless, I'm probably going to use an Amsoil that is specific to older vehicles.

Wayne - they have been pulling the zinc out of the oils big time over the last few years. The zinc is not good for modern catalytic converters and most modern cars have roller cams, so no big deal. But the zinc is crucial for a flat tappet cam! I didn't know it, and always ran regular Castrol GTX 10/30, and my cam lost a lobe, and another lobe was on its way out. You can tell by a loose rocker. But once the lobe is gone, you can't just tighten the rocker - you gotta replace the cam and run an oil with high zinc. Why not pull the valve covers and see.

I'm curious to see if your cam went flat, like it does with so many hot rodders running flat tappet cams these days. If the budget allows, I'd go with a short duration roller cam and Vortec-style heads.

That is some serious power and incredible times! The burnt up tranny a 400 or 350? Great runs, Andy

Man, the sound of that gets the heart pumpin! Awesome......

Holy Ground Pounding Big Block!! That thing looks serious..........

I think you answered your own question - that 70 mile daily trip will kill you with a big block, unless you ran the 700R4 with like a 2.73 or 3.23 gear (which really isn't too bad with that steep 3.06 first gear). If you were just using the car on weekends for fun, I'd do the 454 - the torque is just a blast. Converting to a big block would also nickel and dime you to death with costs such as brackets, belts, hoses, maybe front springs, exhaust, etc, etc........

Looks and sounds great!!!

Nice!!! How about more detailed specs, Sam?

I've got a set of .030 over cast sitting my garage looking for a home! Used. Probably better off with new, though. But if you aren't racing, cast or hyper are fine and will be quieter and burn less oil. Just stick with the big brands.

If it was a complete, intact 4-bolt main 454, then it should have a forged steel crank, big 7/16 rods, and forged pistons (which you probably can't use if you bore it). Great bullet-proof start! A lot of big blocks down here in FL were used in salt water boats, so find out if it was a boat motor. If it was, there could be tons of scale and rust in the water jackets.

Those looked so sexy, I was hoping nobody would walk up behind me whilst viewing!!!

Tim - let us know exactly what you are after performance-wise for this engine. I remember having the stock cam in my LS5 when I first got the car, and it really ran out of breath by 4000 rpms. A slightly more aggressive cam, maybe just under 230 duration at .050, and about 520-535 lift will not affect low end torque a bit, and will give huge mid-range gains. I also ran cast pistons for 22 years straight with that LS5, eventually getting in the 12s, with tons of 6000 rpm (and several accidental near 7000 rpm) passes with no issues. Call it luck, I dunno. Hypers are not bad, but I hear some manufacturers are better than others, so do your homework if you use them. Heck, GM puts Hypers in their 500+ hp Z06 Vettes.

I like using this calculator for compression: http://www.wallaceracing.com/cr_test2.php But I agree - blower motor!!!!!!

Great Job Dave! The pictures don't lie - that suspension is dialed in! What rpm do you cross the traps at?? gear?

Can I state the obvious? No PRND21 in the speedo! Steve - is the neutral safety switch different in the stick cars?

6 weeks ain't bad when your car has been down for 6 months! But some of us are at a snails pace. It will fly by........and its like a deep freeze up there anyways, no?

2 inch Hookers may be overkill on a fairly mild 454, but they fit reasonable well - there are several threads about it. I just did the driver's side on my 502 yesterday, and it requires moving the proportioning valve up and over, and I also have slight contact with the lower control arm mount, which I may have to dimple. I've heard the Hedman 3/4 length fit perfect, but they are only 1 5/8 I believe. With my 454, I ran a Holley Strip Dominator with an 800 dp, drop base air cleaner, and still had room for a 4 inch element (no underhood insulation). There should be plenty of room with a 3 inch element.