We searched swap meets, junkyards, and classified ads for months trying to find the right 454, meaning one that was as complete as possible and that we believed had the potential to run strong without a rebuild. It seems that you rust-belt guys have it good with big-blocks, since trucks fall apart around them and the engines are for sale cheaper than here in SoCal. We had a tough time even finding good crank cores for less than $100, and complete running engines often topped $1,000! We settled on this long-block for $500--a price that would buy us at least four running 350s in virtually complete condition. We searched swap meets, junkyards, and classified ads for months trying to find the right While the seller claimed the engine was an 1985 casting numbers revealed an 1985 intake, 1974 peanut-port (small oval-port) heads, and a 1974 block(arrow). While the seller claimed the engine was an 1985 casting numbers revealed an 1985 intake, 1 Our second clue to the engine’s past life was the yellow machine-shop markings on the front main cap (arrow). That, the Fel-Pro gaskets, and the fact that the oil pump pickup tube was tack-welded to the pump told us it had probably been rebuilt in a decent local shop. The rods were all mismarked with cylinder stampings, but side clearance seemed good. The timing chain was a double-roller and in just-installed condition--including a cam gear installed with two Taiwan Grade 5 bolts with no thread locker on ’em. Our second clue to the engine’s past life was the yellow machine-shop markings on the After jerking the oil pan and the stock cast-iron intake, we found clues as to why the engine was removed. First we spotted a lifter retaining clip (A) in the oil pan, which explained why there was a lifter’s inner plunger (B) lying in the lifter valley. We figured a flat cam lobe and wasted lifter (C) caused both problems, presumably the result of improper cam break-in on this otherwise new engine. Then we found the bent pushrod (closest to the foreground), thanks to a long exhaust pushrod having been installed where one of the shorter intake pushrods was supposed to be. What jokers. We later found a mystery chunk of unknown "oops" (D) under the valvespring with a retainer (E) that was chewed up badly. After jerking the oil pan and the stock cast-iron intake, we found clues as to why the eng We never took the heads off our previous 350 bomber, but felt obligated to go deeper into the 454 considering the money we’d spent. We found the Rat was 0.060-over, which meant 468 cubes but no chance of an inexpensive rebuild in the future. The good news was that there was no ring ridge, the cylinder crosshatch was still there, and the block had been decked so that the piston height was around 0.008 in the hole. With flat-top pistons, compression was about 8.8:1 once we scraped all the carbon off. The engine was reassembled using a complete Fel-Pro gasket set from PAW. Don’t forget that big-blocks require thread sealer on the head bolts. We never took the heads off our previous 350 bomber, but felt obligated to go deeper into We chose a low-cost SSI camshaft for the big-block, selecting a grind that was identical to the one we used in the 350. The only difference was that the lift is greater in the 454 because it uses stock rocker arms with a 1.7:1 ratio instead of the 1.5:1 ratio used in a stock small-block. The specs are: 0.527/0.553 lift, 224/234 degrees of duration at 0.050 tappet lift. We massaged it with cam sauce and stabbed it in with new lifters and our old timing chain. We also had to buy one pushrod to replace the hashed one we found during disassembly. We didn’t degree the cam because we’re not only cheap, we’re lazy We chose a low-cost SSI camshaft for the big-block, selecting a grind that was identical t One bummer about the Rat is that we had to change valvesprings to Crane 99839s to accommodate the cam lift; those are single-style springs that do not require machining. Both the big- and small-block can usually handle up to 0.500 lift with good stock springs, and we got away with the stockers on the 350 thanks to the 0.465/0.488 lift. All the cams with less than 0.500 lift were too weenie for the larger displacement of the big-block, so the springs had to be changed. We also had to buy one new retainer. One bummer about the Rat is that we had to change valvesprings to Crane 99839s to accommod Our 454 came with Taiwan chrome for the oil pan, timing cover, and valve covers, but there was no balancer, pulleys, or water pump. Around here, you could sooner walk to the moon than find that big-block stuff in a junkyard for a fair price, so we were forced to buy PAW chrome replacements. A 396 balancer won’t work on a 454 because the 396 is internally balanced and the 454 is externally balanced (you can tell the 454 unit by the counterweight on the back). We eventually found this balancer at a Goodguys swap meet and smacked the guy down to $20, but we still had to buy a balancer bolt. Our 454 came with Taiwan chrome for the oil pan, timing cover, and valve covers, but there We also learned the high cost of big-block parts when we hunted for an aluminum intake at many swap meets. We paid just $15 for a somewhat mangled Torker intake when we built our 350, but couldn’t find a used big-block unit for under $125. By swinging a deal with the same guy we got the vibration damper from, we finally got an Edelbrock Torker II 2-O for $100. The manifold is designed for large oval ports, and it’s really not recommended for our peanut-ports, but we did it anyway. The carb is the very same 800-cfm double-pumper that had served duty on the 350 small-block. It was $50 at a swap meet. We also learned the high cost of big-block parts when we hunted for an aluminum intake at Another refugee from the 350 was the junkyard HEI distributor--its one of few items that interchange between the two engines. We were able to reuse the small-blocks lower alternator bracket, thermostat housing, fan belt, and plug wires; we also salvaged a few pipe plugs and bolts. The 454 takes different attaching hardware in most places,the water pumps and pulleys are different, and so is the fuel-pump blockoff plate. The El Camino uses a Carter electric fuel pump instead of a mechanical pump. Another refugee from the 350 was the junkyard HEI distributor--its one of few items The good news about the 454 is that it’s virtually a direct swap for the 350. We reused the engine mounts from the small-block, though lining them up on the frame was inexplicably more difficult with the 454. The big-block bolted right up to the TH350 trans because the bellhousing bolt pattern is the same, and the B&M torque converter was double-drilled to accept the flywheel bolt pattern. We sort of butchered the throttle linkage to make it work (not too proudly, though), and the small-block radiator and hoses even lined up. We used the small-block fan and shroud after swapping to a shorter Flex-A-Lite fan spacer, but the shroud is uncomfortably close to the lower pulley because we used a long water pump setup (brackets were more expensive for the short pump). A real big-block shroud and a beefier radiator would be better. The good news about the 454 is that it’s virtually a direct swap for the 350. We reus We cheated: We actually found a set of big-block Chevelle headers at a Goodguys swap meet for $8, but we didn’t want to carry them home. We listed the $8 price in the chart, but we really used a trick set of coated Hedman Hedders we had leftover from a dyno session. They fit perfectly--in fact, we’d say they’re easier to work on than the small-block headers in the same car. We cheated: We actually found a set of big-block Chevelle headers at a Goodguys swap meet Here’s what the fat-block looked like once it was all bolted up and ready to go with the same Carter electric fuel pump and NOS Power Shot nitrous unit we’d used on the 350. The 454 bumped up the Elco’s weight from 3,250 to 3,400 pounds, and the nose sagged about 11/4 inches. That gave the car a good stance, but the wasted shocks get really bouncy with the big-block weight, and the handling is noticeably worse than it was before. The manual steering doesn’t seem much heavier, but the brakes sure do. Here’s what the fat-block looked like once it was all bolted up and ready to go with You've seen this story before. Both Hot Rod and Chevy High Performance have taken a whack at the "big-block versus small-block" concept a couple of times, usually with informative results. Recently, both magazines ran a story wherein two engines were built, dyno'd, and run at the track. One was a small-block and the other a big-block, and they both displaced 408ci to take the displacement issue out of the study and simply find which engine had a better design. Ultimately, the Rat trounced the Mouse both on the dyno (by 22 lb-ft and 41 hp) and at the strip (12.31 versus 12.59). They claimed the Rat cost about $4,500, only $850 more than the small-block (neither price included frivolities like a carb, ignition, headers, pulleys, hardware, or chemicals). It was an interesting study that made for a frenzy of bench racing. But then it occurred to us: Who pays $4,500 to build a big-block that's only 408 cubes? We're just a bunch of dirtbags trying to go fast for cheap with a worthless El Camino, so theory means little to us. In an attempt to let the Rat and Mouse face off in a more practical scenario, we decided to look at the real price and performance of a used 350 with basic bolt-ons versus a second-hand 454 with the same upgrades. We've practically broken our arms patting ourselves on the back for making our small-block-powered El Cheapo '72 run 12.93 at 103 mph for a total investment in the entire car of $1,994.87 (see "12s for $1,995," May '99). All that was involved was a used 350 with a cam, headers, a single-plane intake, a theory-be-damned 800 double-pumper, a used TH350, and a swap-meet nitrous system. And you're right, high 12s on spray isn't that impressive--until you learn that the car has 2.56:1 rearend gears. How quick would the same car run with all the same stuff hung on a 454? Would it be worth the extra price? Read on to find out. Enjoyed this Post? 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