Battle of the Blocks | SBC 400 vs Pontiac 400

throughout the 60s and 70s Pontiac and Chevy went Head to Head [Music] there might be cousins from GM but they attract a completely different buyers now that being said both manufacturers produced a 400 cubic inch engine now this was achieved with a 4.12 by 3.75 inch stroke on both engines which means that they should perform really similarly now we're using 1976 numbers here these are Smog era numbers which means you're probably going to find these engines on Marketplace eBay or just down the road for me for sale so the 1976 Chevelle was rated at 175 horsepower at 3600 RPM and 305 from all the torque at 2000 RPM the Pontiac like Trans Am for instance was rated 185 horsepower at 3600 RPM same RPM and 310 pounds of torque at 1600 RPM now a little lower RPM there typically that's due to Pontiac having less Runner volume longer Runners and just trying to get that Port velocity up now this obviously changes pretty heavily once you start modifying the engine typically you're gonna run into more compression and bigger intake Runners when you start swapping heads so what does that mean for you first let's take a look at the Pontiac most guys with Pontiac will run Edelbrock heads an RPM air gap dual plane intake one and 70th inch headers with like 38 inch primaries and a crane hr242 cam this is a 242 252 at 114 degree LSA uh 0.558 lift on intake and exhaust and it performs very very well in this engine now we're looking at 502 horsepower at 6000 RPM and 499 phones of torque at 4500 RPM that's a pretty respectable engine and it's kind of expensive build for what it is but it's going to be extremely fun engine when you get down to it now let's compare that to the Chevrolet small block 400. so on the small block 400 we're going to run flowtech 220cc heads these are actually under about a grand for a pair assembled one and seven inches headers another Edelbrock RPM air gap intake and the HR 240 cam that's available in the small block now the HR 240 is a little bit smaller can than we find in the Pontiac but that being said it does have a little higher lift so we're sitting at 240 248 114 degree LSA and 0.595 intake and exhaust lift meaning it's got a little more exhaust lift with a little less duration than that of the Pontiac so it should perform fairly similarly if not give you a little bit more low end powder so let's go ahead and compare these two on the dyno sheet but before we do that let's take a note of 502 horsepower at 6000 RPM and 491 from the torque at 4 500 RPM so it's really really close to that Pontiac that being said if we go ahead and overlap these two it is pretty much exactly overlapped other than at the very the very Peak now the big difference here is going to be the average horsepower in the range we're seeing a 26500 RPM even though you're gonna shift this at probably about 6200 RPM so we're sitting at 356 average horsepower and 430 average responsive torque throughout that range now on the Pontiac it's sitting at 360 average horsepower in that range and 437 for pounds of torque average throughout that range meaning the Pontiac has a very slight advantage and it might beat out that Chevrolet a few times but it's going to come down to the driver conditions lost through the transmission and rear end gears all the other stuff is going to matter more than the engine themselves going head to head as they are essentially the same Power Band the same torque the same horsepower now what this means for you is if you're a small block guy the 400 is basically the engine that will compete with Pontiacs also the 400 small block is less weight than the 400 with Pontiac because I mean we all know the 400 Pontiac is the same block the same block Dimensions as the 326 350 the 400 the 428 and the 455. meanwhile the 400 small block is the biggest one available of the small block from Factory unless you you know born stroke and all that good stuff but you can do that in this Pontiac as well so in my mind the small block 400 has a distinct advantage over the Pontiac 400 now that's not only because of weight but also because of price to to set the stuff up lbrock heads aren't cheap right so you can usually build this 400 small block for about the same price you're gonna pay for heads on the Pontiac so it's really up to you guys what you guys think comment down below let me know what you guys think what engine you would run in your car and why but I hope to see you guys Wednesday at 9 00 PM East for a few discussions about Pontiac and small block engines

Channel: LSxHunter

Views: 24,229

Keywords: restomod, car build, classic car, muscle cars, small block chevy, sbc 400, pontiac 400

Id: EpdbgdHWM8E

Length: 4min 53sec (293 seconds)

Published: Sun Jan 22 2023