a guy i work with insists that the 305 is piece of garbage when it comes to performance. he insists that the 302 is a much better performance engine. i disagree with him 100%. comparing my camaro RS 305 with a fox body 302 mustang is not a fair contest. when GM sold my car new they crippled her with a 2-1/4 poor flowing exhuast, a bad-for-performance cam, restrictive intake, and 2.77 rear gears, and to boot its heavier than a fox body mustang. no wonder it would never stand a chance. GM never factory built a really high performance 305. the 350 always got the better hardware. so block for block i think the 305 is every bit as good as a 302. the 305 is a great engine in my opinion and was never given a fair chance to fight out the factory. any thoughts?

 

The Ford and Chevy 302 has a 4.000" bore, same as a Chevy 327 and 350, which allows for larger valves and more airflow into the engine.

The Chevy 305 has a 3.73" bore, about .26" smaller. It might not seem like much, but a 1/4" is huge when it comes to engines. The smaller bore of the 305 limits the valve size and prohibits proper airflow into the engine. Yes you can make a 305 fast, but it takes more money and time to do it.

 

Head bolt placement is also an issue with Chevy vs. Ford. Ford heads only have 4 head bolts per cylinder, which greatly opens up the port area into and out of the cylinders.

 

guess as far as your opinion goes you're right in your mind but in your post you admit your friend is correct and even give fact to suppot is side. truth is the ford 302 is far better than the chevy 305 for the resons you already gave. big assest to the ford is the 4 head bolts per cylinder that doesn't restrict the exhust ports near as much as the 5 on the chevy do. the 302 chevy is more than the equal of the ford 302, but it comes into it's power range at higher RPMS and tends to be a dog in the lower ranges.

 

Sadly, its true. The 305 is a pig!

Any motor can be built up to 99999hp, but my money is on the ford 302 getting there faster and cheaper.

 

The guy at work is right, Ford 5.0 FTW. And before the roller valvetrain hit, Ford had another advantage there with bigger lifters.

 

ford 302 blocks split at 450-500hp

chevy 305 blocks can take as much as a 350, like 700hp

that really ony comes into play when your dealing with forced induction though, it's really hard to make an N/A 700hp 305.

 

To start off i would like to say that i actually like fox body mustangs and i think they were equipped with a great drivetrain combination, BUT:::I would never drive a mustang PERIOD.
I have several friends with modded 5.0 mustangs all of them being 5 speeds with gears and the whole bit. My car being a automatic 305 tpi car with the horrible 2.73's doesn't stand a chance from a stop/ roll you name it.I always thought i would be able to keep up with one that was more comparable to mine.
Sure as **** my other friend just got an bone stock automatic 5.0 with 2.73's as well. And just as I had thought i beat him bye a good 2 car lengths. I was totally impressed with my car and felt proud and that i finally proved a point to my friends with the 5 speed cars that i dont have a slow roc'
Haha sorry about the long read but I knew you would enjoy

 

The little 302 Mustangs had many advantages over the 305 TPI cars of the day- and the engine design only had a little to do with it.

Bigger bore on a 302 meant you could use larger valves, but the valves in original 5.0 EFI motors wren't much larger than the Chevy 305s of the day- and the heads didn't flow much more, if any. 225HP on a Ford 5.0 was almost exactly what a 305 TPI motor put out (manual trans with the good cam- automatic TPIs got the pathetic peanut cam) and the torque curves were similar. Stock 5.0 mustangs couldn't really rev much better than a 305 TPI- they were all done around 5500, too. When modifying, yes, there were advantages with the larger bore of the Ford 302.

4 vs. 5 head bolts has plusses an minuses. The larger number of head bolts on a SBC isn't really a factor in restricting the ports. To some extent it's becuase Chevys siamese 2 intake ports together (EIIEEIIE), where the Ford does a straight-up IEIEIEIE setup. When you simamese the intakes together it means you have to squeeze 2 intake ports between pushrods- there will be a choke point there, but again, that's far from being a meaningful restriction on a stock SBC head. And, of course, having only 4 head bolts on the Ford means they don't do a good a job sealing up the head gasket as a SBC with 5 per cylinder- an important consideration for nitrous and boosted applications.

The REAL reason 5.0 Mustangs usually whipped on TPI cars back in the day....... Mustangs of the day were much lighter than F-bodies (several hundred pounds, typically) and usually geared better. Same power in a lighter, better-geared car meant they could kick sand in a 5.0 TPI car's face most times. The other reason is NUMBERS. Ford built half a trillion 5.0 Mustangs- the aftermarket went wild with catalogs full of inexpensive performance parts for them. The TPI motors never got the same level of acceptance and support. Any dope could buy a pile of parts from a catalog and get his Stang into the 12s or 11s. TPI guys just didn't have that ready-access to scores of inexpensive aftermarket parts- and their cars still weighed more.

 

The Ford 5.0 imo is a better engine than the Chevy 305, for all the reasons mentioned above.

But you know what will whoop thier 5.0 ***? The Ford 2.3 Turbo. With just simple mods as a Large Intercooler, T4 Compressor (or Holset) and 20pounds of boost, you will be making close to 300hp. This is the limit of the Stock ECM, VAM and Injectors. Throw a Megasquirt on there with a little larger injectors and you can easily make 400hp on a stock block.

Its funny, my little 2.3L 4cyl turbocoupe will lay the smackdown on most 5.0 and 4.6.

 

ROFL, when I first started driving I had a T-bird with that exact power plant in it. At 15 psi of boost it really didn't have too much problem waxing most bolt-on 5.0s. Ran very well for what it was.

 

Heck yeah, that little 2.3 is a beast! No torque though unless you have the IHI Turbo, but then again it runs out a breath at 17-18psi.

I have the Ford Motorsport A234 cam it in with a TO4B V-Trim, Ported E6 Manifold and a HUGE intercooler running 20psi, after 3000rpm this thing just pulls and pulls and pulls, wish my 350 was like that. Also, i also run 87 Octane with no detonation at all. If i Megasquirt it i could easily be putting down 400hp with a little head porting and 25psi of boost. (i dont think the clutch can take it tho)

The only real reason i am getting into the IROC is its very nice car, i was instantly sold when i went to look at it, and the TBird needs alot of work, 5lug Conversion, Paint, Wheels, Interior, Volvo 16valve head... etc.

 

How did this become about turbos? Cram massive boost into anything and I'll fly or blow up. Duh.
Look at any aftermarket heads and the SBFord will have higher port flow than the same company's comparable SBChevy heads. GM 305's were designed to be torque motors, and the "top drawer"TPI systems were optional, so had nowhere near the numbers and aftermarket support as the GT/LX 5.0, which ALL came with the Port injection system, and responded very well to mods.

The 350s when they became available were highly restriced by the TPI system, a good cam and a carb on a TPI 305-350 will bring amazing results. But bolt-on for Bolt-on, the Ford 5.0 will give you better results (trust me, I work for the NMRA on weekends), because you have to rev any engine to get serious power, and the entire GM 305 package, from air filter to tailpipe is designed to be most efficient at low RPMS, so to make big power, you pretty much have to replace EVERYTHING, including the long stroke/small bore engine. I much prefer the TransAm/Camaro as a drivers car, but that is reality. Sorry