Yeret

Penetrating oil trick didn't work, engine's still not budging. I'm gonna just go ahead and say that the engine is just plain gonna need a rebuild.

Before I continue any further, I'm not looking for "just swap in a 350" responses. Yes, I'm well aware that it'll cost the same, maybe less, to build a 350 and get more power, but I'm just more interested in keeping the car original (save for going the stroker route, if I go that way).

So anyway, I kinda got to thinking. Since I'm gonna go through the trouble and expense of rebuilding the engine, and because I'm always one to give thought to the "different" route, what would happen if I went the stroker route? The overall proceedings seem to be basically the same as stroking a 350. What I'm looking to do is stroke the 305 but keep all the factory stuff. I have read before that, with proper tuning, stroking an engine without changing anything else will increase the peak torque by 20-30%. Since the 305 has a relatively small bore and the stroke increase isn't enormous, let's say that the engine will gain 20% more torque. Assuming 285 lbs from a factory engine, 285 * 1.2 = 342. That's an increase of 57 lbs of the spinny stuff. Since the 305 has a small bore, I don't imagine the horsepower is going to increase as proportionately.

Yeah, why would I even bother but then, why not? A stroker crank, pistons and block clearancing is going to add a bit overall to the tab but screw it. With this setup, are my humble expectations correct? Will the engine generate more torque but less horsepower than a 350?

dmccain

iTrader: (2)

Nope. May be a fun lil engine but nope.

Orr89RocZ

iTrader: (20)

Using same cam as a L98 350 lets say, the smaller 305 bore and valve size would likely not make more torque but hard to say. Torque is airflow. Stroke helps generate piston velocity which helps cylinder fill since it draws on the intake port but small bore and valve hurts flow

red rock

iTrader: (2)

The old saying,"no replacement for displacement" still holds true. If you want to stay "original", just rebuild the 305 back to a 305. There are a lot of threads on here about building more HP in a 305. Cost wise, and efficiency wise, just fresh'n up the 305 block and you will be at or a little over stock already.

Drew

iTrader: (58)

You see all the wicked fast 334 strokers around here? Me neither. Sheet dawg, it's hard enough making a TPI 350 fast.

KyleF

It's going to be disappointing. You will spend a lot of money for not much gain.

I know you don't want the just build a 350 response, but you said you want to keep the car looking stock. To be honest, if you had a 383 under a TPI manifold... what wouldn't look stock? Unless someone just wanted to crawl around looking for casting numbers?

If you want to build a fast 5.0L stroker, you need to go buy a 5.0 Ford. Their bores are bigger and do not shroud the valve. The biggest issue with a 305 is the bore in relation to intake valve.

for 30 years people have been wanting to hop up these 305s. There is a lack of support and a lack of cars popping up with hot 305's for a reason. If you just want the challenge, pretty much follow the same recipes for a 350 and just expect less output.

QwkTrip

iTrader: (22)

Every car looks stock with the hood down.

NoEmissions84TA

iTrader: (1)

I have a 334. Given the choice between stroking the 305 (334), installing a 350, or stroking a 350 (383), I would choose the 383. 383 kits are now cheap and basically plug-and-play. Doing a 334 is much more expensive and getting all the parts to work together is a real PITA! Nearly everything will be custom. And then you still have the problem of the 305's small bore. Yes, it can be a fun engine, but you will pay twice as much for it. Just DON'T DO IT!

Yeret

Thanks for the input, guys. No love at all for a long armed 305 then? I'll start doing some more research. Once upon a time, I knew quite a bit about small block Chevies but then I started getting into Mopar engines. I still know a decent bit but still gotta relearn what works and what doesn't.

Also, just to muddy things up a bit more, let's say I buy a 350 short block and transfer my stuff on to it. I know that the 305 heads have something like 1.85" intake valves, which will be pretty small on a 350. Would it be worth it to port these to 1.94" to match the 350-spec heads or would I be further ahead just buying some new heads entirely? Would 2.02" be excessive with the Tuned Port induction and, assuming everything else is OEM-spec, would this require tuning of the PROM? I'm hoping to simply nab a base Corvette chip, snap it in and go.

Orr89RocZ

iTrader: (20)

305 head wont hurt a mild tpi 350 to bad. 1.94 is better but depends on what you want to do. Anything bigger and aftermarket will require tuning and better intake manifold to flow best to get your moneys worth in power

If you dont tune your own stuff, and if you cant find a 350 L98 spec head then just use the 305’s.

KyleF

Not all 305 heads are the same. You will have a smaller combustion chamber though and will have a higher compression ratio. This could be a good thing if you do it right.

When I was 18 way back when, I had the desire to build a hot 305 when my 305 TPI spun a main. Well... I ended up picking up a 350 block for $50 off a buddy's garage, used the SLP Cam and Runners, Port matched everything, 24#/hr injectors, longtubes, and other supporting mods later I was rocking a 350 with 305 heads. The 700R4 had been rebuilt with a shift kit. It had a 2.77 rear but since it hadn't broke I hadn't replaced it. I was balling on a budget.

In the end I could hang with a LT1 6-speed 3.42 car from any speed or a dig and could pull a LT-1 Auto 2.73 car from any speed or a dig. I dreamed of a 3.42 rear and 195 AFR heads... but then I got a TTA and a lot of other cars since.

The big thing on a 305 is the bore diameter and side wall in relation to the intake valve. You will not be able to fight the physics of this situation.

NoEmissions84TA

iTrader: (1)

You said you got into Mopar engines. Did any of those have bore notches?
Because that is what I had to do with my 334. https://www.thirdgen.org/forums/tech...ml#post6128098

Fast355

iTrader: (2)

Not sure on the Mopars except the 318 Hotrod built about 10 years ago.

That being said ALOT if not all 396/402s factory high performance engines had notches.

zya5point0

iTrader: (4)

If I was on a budget and just wanted "a little more" than the stock 305, browse Craigslist for a TBI 350 from an early 90's (non vortec) pickup. I've seen running motors for $500. You'd have a one piece rear main roller cam 350 engine for not a lot of money with a good foundation for upgrades later. Throw in some lt1 injectors and a factory l98 chip and you'd have a good running car till you can afford more later.

Yeret

I read of a 318 build from Hot Rod a while back, titled "Junkyard Jewel." They built a pretty badass 318 engine and among the mods were porting the factory heads to take 2.02" intake valves. They did have to notch the cylinders to fit the valves, due to the 318's 3.91" bore, but I have read of people not having issues with this, although those people used aftermarket heads. Perhaps there's a difference in valve angle?