Clever Idiot Posted December 27, 2012 Share Posted December 27, 2012 I'm sure some members have gone through it. I'm thinking about upgrading my 350 to a 454, and I'm wondering what pitfalls I should look out for when considering. I know I'll need to change the front springs, but other than that, I'm pretty clueless. Car's apart, the only thing I have installed is the fuel and brake lines. Are the fuel lines different (tank-to-pump)? I have a 12-bolt I bought off Jared that came out of a '71. I was planning on just rebuilding my TH350 to get it back on the road, or perhaps put in a stout 200-4r if money allowed. Would those transmissions handle a 454? Any drive shaft mods required? What else should I look out for? Quote Link to comment Share on other sites More sharing options...
monte70car Posted December 27, 2012 Share Posted December 27, 2012 headers, front drive system, a 350 trans will live behind a big block but an upgrade to the internals will need to be made if it's going to be raced. As for the overdrive option the 200r4 is the same length as a 350 so the only thing to change is the yoke and the trans is a easy swap. Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted December 27, 2012 Share Posted December 27, 2012 one thing to really need to think about here is the cost of gasoline, if you like to drive it, and with the way our economy is, a 454 is a thirsty monster Quote Link to comment Share on other sites More sharing options...
Clever Idiot Posted December 27, 2012 Author Share Posted December 27, 2012 No racing for me. Just a streeter with a lot of push. Planned on upgrading the trans internals at some point anyway - Bowtie Overdrives is where I was planning on getting the trans. I like the 200-4r because of its length; I had heard/read somewhere the same thing so I figured it would be an easier swap. Need a whole new exhaust system anyway, so that's no extra cost. Same story for brake booster - I need a new one anyway. Don't the big blocks need a smaller diameter booster for clearance? Front drive system - you mean the accessories like power steering pump, alternator, etc? I need new ones for my existing 350 as it is, so again no extra cost there. What about motor mounts? Same mounts/location? Quote Link to comment Share on other sites More sharing options...
Clever Idiot Posted December 27, 2012 Author Share Posted December 27, 2012 one thing to really need to think about here is the cost of gasoline, if you like to drive it, and with the way our economy is, a 454 is a thirsty monster No doubt! If I don't go 454, I'm planning on building my 350 to be around 400hp/400ft-lbs so I figured it would be plenty thirsty on its own. Although I would expect a 454 to be even thirstier. Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted December 27, 2012 Share Posted December 27, 2012 more cu.in. the more air it sucks, the more air it sucks, the more gas it needs! you can still get save lots of gas if you keep those secondaries closed! Quote Link to comment Share on other sites More sharing options...
bigtankjones Posted December 27, 2012 Share Posted December 27, 2012 more cu.in. the more air it sucks, the more air it sucks, the more gas it needs! you can still get save lots of gas if you keep those secondaries closed! You can use the same motor mounts as the 350. I'm using my TH350 behind my 454. Mine is pretty much bone stock other that the after market intake,4160 Holley 750 and headers. Just keep your foot out of it like Sam say's. Quote Link to comment Share on other sites More sharing options...
gprimm Posted December 27, 2012 Share Posted December 27, 2012 Brake booster is the same. Here are some differences between the small block and big block. 1). Fuel line from rear should be a different size. 2). Radiator, will need bigger. 3). Front springs 4). Radiator fan shroud 5). A/C brackets, if it has AC now and you want to keep it. Quote Link to comment Share on other sites More sharing options...
bigtankjones Posted December 27, 2012 Share Posted December 27, 2012 Brake booster is the same. Here are some differences between the small block and big block. 1). Fuel line from rear should be a different size. 2). Radiator, will need bigger. 3). Front springs 4). Radiator fan shroud 5). A/C brackets, if it has AC now and you want to keep it. I have reused my small block fan shroud with the Big Block,also have reused my Radiator to with no overheating issues. Mine was a A/C car but I threw that stuff away. I have about an 1 1/2 inch clearance between to shroud and the alt/pulley. But if you want your car to look correct you wont do what I did. Quote Link to comment Share on other sites More sharing options...
MGD72Monte Posted December 27, 2012 Share Posted December 27, 2012 I'm with Sam on this one, it is already expensive enough to drive a 350, and the future is unlikely to be getting cheaper. If it is not for racing or original to the car, I'd be sticking with a 350. You can get a lot of HP out of a 350 and with the right exhaust, the sound of a 350 can be perfect. Good luck whatever your decision, your car will be awesome I'm sure. Quote Link to comment Share on other sites More sharing options...
Mo's70MCs Posted December 27, 2012 Share Posted December 27, 2012 A stroked SBC will have plenty of power or a built one..and besides after the time, money, and effort you have spent on that beauty I'd be incline to believe you'll be easy on the H.P. Quote Link to comment Share on other sites More sharing options...
ripleydale Posted December 27, 2012 Share Posted December 27, 2012 One thing you might want to consider is if you're putting on headers, an aluminum intake, and getting rid of air conditioning, your small block springs might be just fine. Quote Link to comment Share on other sites More sharing options...
72MC Posted December 28, 2012 Share Posted December 28, 2012 I have new small block(with A/C) front springs in my El Camino with a 402 BBC and it sits great. Seems to have the stiffness I desired. - Dave Quote Link to comment Share on other sites More sharing options...
Clever Idiot Posted December 28, 2012 Author Share Posted December 28, 2012 Well, after looking into a few different avenues I've decided to stick with the 350 to get it back on the road at the very least. I can build up the 350 slowly once it's on the road, and if it ends up not being enough I can swap it out later. As for fan shroud, I'm going electric, so it's gone already. Radiator I'm already going for an aluminum 1" dual core - not sure if that would be enough for a 454, but I would think so. I think I remember reading somewhere it's equivalent to a 1/2" 5-core copper (if such a thing were possible without diminishing returns). A/C will definitely be going in. This is Florida, man. That stuff is NOT an option. A bigger fuel line will be a PITA. I already have the 3/8" stainless line installed, and the body on the frame. Changing it now would be prohibitive. Yeah, all things considered, I'm going to stick with the small block for now. Get this girl back on the road and then see if I can't get enough power out of it. Thanks for all the input, everybody! Quote Link to comment Share on other sites More sharing options...
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