I have a 65 mustang with a 302 and just bought a edelbrock rpm intake with the 600 4 barrel carb? how much extra horsepower will this add to the stock 302 and how much horsepower do stock 302's have? I was also am going to take it to the shop to get it to 400 horsepower. My dad isn't to fond of this idea and i wanted to know is 400 horsepower in a older mustang good for reliability and is this too much horsepower? I do not think so but i also have never been in a car that has 400 horsepower.

 

Power from a stock 302 depends on the 302. As far as power gain from the carb and intake....10-20, but it's gonna depend on what heads/cam it has and what intake you went from. Going from a crappy2bbl intake and carb to a good 4bbl intake and carb will net decent power gains.And if you want 400hp out of a 302 I hope you have a really good job, cuz it's not cheap. It can be done but will cost money, then you need to have a drivetrain and suspension that can support it. And you need to know how to drive with that kind of power and not kill yourself or someone else

 

Learn to drive with what you have before searching for heaps more power. Given your 302 is probably only putting down about 170 hp to the rears, double that becomes a handfull.

 

what would be a good horsepower range without having to change the suspension?

 

How about this. Do some basic suspension upgrades before looking for more power.Shelby drop, larger sway bar, better shocks new bushes etc.Brakes aswell. Upgrade you brakes before going for power.
Sorry to sound like an old fart (im really not that old) but these old cars were not designed to cope with the power that can be wrung out of them. Adding to this is that they are upwards of 40 years old, so there can be some significant wear and tear that needs looking at before you can safely up the power. The time it takes tou to get through these upgrades will be valuable time spent gaining driving experience.

 

ya i was driving it like a maniacover the summer until the transmission went out. now that i got that up i want to redo the engine but never thought of redoing the suspension.

 

That 600CFM carb is big for a stock 302. It should be driveable with some tuning, but you'd get better throttle response from a 500CFM carb.

And yeah, upgrade the suspension and brakes first, then worry about an engine build.

 

i havent bought the 600 yet but it comes in today, im thinking of buying the 600 due to us taking the engine to get bored over this weekend and getting bigger cam pistons, heads, roller rockers, lifters. And i have the money to get it also, the shop says they got a 302 to 427 hp but im looking around 400, so do you think even running it seldomly and not racing it, it will still have suspension problems?

 

The 600CFM carb will work well with mods.

A 400+hp 302 is a monster smallblock, and unless it's got a blower on it, it's going to be near-unstreetable, even with a modernized suspension. I have a 320hp 331 stroker in my 67fb and it's nearing the upper limits of streetability. You have to understand that once you pass the 1hp/cubic inch mark, power starts to become increasingly expensive, and usually comes at the cost of reliability and driveability.

The only way to pull 400hp from a 302 is by moving the power band up the rpm scale (and use some expensive heads). The problem with that is that you sacrifice power at lower rpm's, where you're going to be spending most of your time while driving on the street. Throttle response and gas mileage will suffer. It'll be fine for a weekend warrior, but not for something that gets driven often.

Not to mention, the rest of the car isn't set up to handle nearly that much power. At the very least you'd need better springs and shocks, better brakes, a new rear end (not just gears), and subframe connectors.

If you have to rebuild the engine (you haven't actually said that it NEEDS to be done), have them do a mild rebuild and spend the rest of the money on suspension and brakes. The kind of rebuild you're talking about is going to cost $6-8k. You can get a mild rebuild done for $2-3k and completely redo your suspension and brakes with the rest, and probably still have some leftover.

 

If you don't have good suspension but a lot of power, every time you get on the throttle the car's just gonna go all over the place. It'll wheel hop like mad, get sideways on launch, get unresponsive under power etc. Definately start with brakes and suspension. As far as a 302, you can get 400hp or even 450hp at the crank and have it streetable(but that's pushing the absolute limit of streetability in a n/a 302and using the best available modern parts and you REALLY have to know what you're doing), but you're basically gonna have stock nothing except the block and perhaps the crank, and it will be very VERY expensive. For most builds 400hp is really pushing the streetability limits without forced induction on a 302 like Starfury said(and that's with good heads, cam etc). If you want over 400 streetable horsepower out of an all engine 302 you better be ready to drop a minimum of $7,000k into just the engine with you doing all the labor except machining. Then when you add in suspension, brakes and transmission to support it you easily break the $10,000 mark. Start with some suspension and brakes, then build a nice 302, and shoot for the 300-350hp range, it's much cheaper and easier to do, and a far more realistic goal for a first time performance engine. Horsepower does NOT come cheaply or easily. In order to get about 375hp from my 302 all engineturning around6,000rpm I had to put about $5,000-6,000 into it, and that was with me building it. The only truely stock part left is the block...it has a production crank but even that has been modified and the internal configuration isn't even standard. It seems like you're trying to bite off more than you can chew, you need to start slower and not just jump straight into a high horsepower engine