i would say go Big block if you can afford it and yeah building it yourself will really cut down on cost. a 450-500hp big block is kind of mild. you could do that with a 454 and good heads and a cam. The torque can't be beat with a big block and if you wanna cut down on weight then you could get some nice alum heads like AFR's or Brodix and that would save like ~80lbs on the front.

I'm getting a 468 big block with around 570hp and i'm just using the 781 GM heads with CNC porting and bigger valves and a solid roller cam with 10:1cr. a 383 would be nice because its lighter but the large torque of the big blocks is just awesome and the sound is amazing too! Also a 500hp 383 is gonna be pretty radical but the extra cubes of the 454 would really help if you want it to be streetable at all. some people build some nice 406 or 408 small blocks also

I know you don't plan on driving it on the highway much but I don't think I would put 4.56's in with a torquey big block unless you plan on strictly racing it because if you ever do decide to go on a cruise, your RPMS will be way too high. you will need very good traction to get it too hook with all the torque and such low gears.

 

Jason,

That is very true about the gears... I apologize for some of my incompetence about motors. But I've got to figure this stuff out somewhere. I was also looking at some blown 383 applications with a weiand 144 supercharger where they have made 500hp plus on 91 octane. I honestly just can't decide. I don't want to get halfway through building a bbc, and then change my mind and think **** I should have gone blown sbc!! I could get a decent 383 kit for around 1k, and heads for not much, and 144 superchargers aren't terribly expensive... although if I bought a 454 and simply swapped the cam/pushrods/lifters/rockers and springs with a nice set of heads, you think 500hp with a heavy cam is possible? Could I just keep the stock crank connecting rods and pistons? What would you do?

 

Oh it's cool Rogue, I'm not an expert either but just passing on info that I have learned. yeah a blown 383 would be sweet but if you want a blower than it's best to go procharger IMO. but I also love a big 6-71 or 8-71 blower sticking out of the hood Blown engines are trickier to tune. Yeah there are lots of options out there and it drove me nuts trying to decide too but i eventually decided on the BB. But yeah you don't wanna change gears halfway through since it wastes time and money so think about all of the options. I think I would go N/A though since anykind of FI would require more money and time spent tuning. If you get FI you will need to upgrade to forged internals and lower cr pistions and the supercharger itself can cost around 3-5k.

keep in mind though if you go to around 450-500hp you will need to build up your trans and rear end especially if you plan on racing it. well i think you can get 500hp with a good set of heads, compression and a good sized cam especially a solid roller as those really wake up the engine. You could probably use the stock crank and rods since they can take quite a bit of power but mise well just build it once with good parts, just incase. I would personally build either a 383 or 408ci SB or 454 BB. i think you would be happy with either

 

The more I think about it, I'm warming up to the naturally aspirated 454. That was a very good point about FI being harder to tune, and would be much trickier to dial in. Have you ever had any luck scouting for an engine at a salvage yard? I've heard stories of guys finding 454's for about 200 bucks complete which is very very tempting. Have you installed your motor yet? Did you rebuild it or buy it crate? Also, what gears would you suggest running with a bbc? Since they wrap out much lower than small blocks, what gears are you running? Your car also looks terrific by the way, I love 2nd gens!!

 

well make sure that the engine you decide on is really what you want and can afford and will work with your goals for the car. I love the power big blocks have and the potential for even more power should you decide too. They sound amazing too! Love it! i haven't looked for a big block at a salvage yard but have seen a few on craigslist locally that didn't seem too bad of a deal. No i haven't installed the motor yet, I'm waiting until i can afford to swap my trans. It's built by a engine shop but i kind of wish i built it since it would be cheaper. well my car is mostly street with maybe a few strip visits so i'm planning on using 3.73 or 4.10 gears but i also am going to swap in a 4L80 OD trans. If your gonna use your 4 speed then I wouldn't go lower than 3.73 and you will probably have traction issues. I would go 3.42 if you didn't wanna race it much for a good balance of RPMS and acceleration. but if you don't wanna drive on the freeway much then you might get away with 3.73's.

Oh thanks! your car looks sweet too! I also love 2nd gens! I can't wait til i can get it painted though

 

How much did the shop charge to build yours? Do you have any knowledge on what rebuilding a 454 would run me? If I could do it for around 2500-3k I would be pleased. I really want to keep my 4 speed in it, I just like shifting gears. If it was strictly a track car I would definitely put an auto in her. What I was thinking is that I could find someone with knowledge of big blocks that could help me blue print the parts I would need, and then take some night classes at the local community college and rebuild it there that way I would be sure to do it correctly.

 

well they charged like 7000 but because it's turn key, all forged and with the solid roller. Well you could probably build a 454 yourself for under 3k if you used the stock heads but ported them and got a nice cam but if you go aftermarket heads that can cost 2k alone then it would cost you a little more. but you can get 450-500hp with the stock heads (ported with bigger valves), 781 or 049 heads are the best stock heads. Yeah i kind of wish mine had a 4 speed but i don't wanna convert mine so i'm just gonna do a manual valve body 4L80 trans. yeah that would work and they also have books on rebuilding engines that might be helpful too.

 

I also have a follow up question I forgot to ask. If I were to replace the rotating assembly of a 454, should I just stroke it with a 4.250 crank and bore it .060 over to make a 496? It wouldn't cost much more to just stroke it, and while its in the machine shop anyway I might as well bore it??? What heads seem to be popular for big blocks in aspect of bang for your buck

 

yeah i was going to mention that earlier too. it doesn't cost much more to stroke it and if your gonna tear it apart anyway then I would stroke it to a 496. mines bored .030 over to a 468. you could have a relatively mild 550-600hp engine. well for your power goal of 500hp you could just use the 781 or 049 GM heads but if you wanted aftermarket heads the best are AFR but Brodix's are also good

 

This info has helped out so much. I know about AFR's, I've heard very good things about them, but again I didn't pay much attention to big blocks and still don't know much about them. I think tomorrow I'm going to give a few salvage yards a call and see what I can dig up. I found a couple decent deals on craigslist too, but if I can get one cheaper at a salvage yard I'll probably go that route. What are you running as far as intake and carb setup? More hp/tq equals more fuel/air demands also, so I should probably upgrade to an electric high performance fuel pump. Have you beefed up your rear end? Do you think traction bars will do the job or? Sorry for all the questions!! haha I'm simply curious as to what your general setup is going to be once you've got all that power in your 81!!