I have an 84 Z28, 305HO (VIN G) and this is the engine I plan on rebuilding, so no detractors please. I already have the engine and this is what I am going with. Engine Power made 305hp with a cam from comp cams (Xtreme Energy CL -12-422-8: 218/224, 0.495/0.502, LSA 110). I was looking around and saw the Melling 22135 (214/206, 0.490/0.470, LSA 112). It is considerably less expensive, but the numbers are not quite as good.

Overall, this is a daily, not a race car. It is a ragtop with the idea of just nice street cruising, but if I hit the gas I want to be able to get there a little more quickly and with a smile. I currently have an Edelbrock Performer intake, Edelbrock 650 cfm carb, and plan on roller rockers, shorty mufflers (would love suggestions for that as well) and a Flowmaster exhaust. My goal would be 300hp at the wheel, but even 250-300 should be a little better than the 195 (dyno tested) that I had at the wheels on the stock (other than intake and carb) setup.

So primary questions: is the Comp cam worth the extra money to get me over the 300hp line, or will the Melling get me there, too? Or is there another you would suggest? For headers, any specifics to look into or avoid? And finally, other than start over with a different engine, suggestions?

 

Yeah, id use the comp cam. And potentially look into a roller conversion as well. Id recommend dons headers. They're overkill for a 305 but they are great and fit well. You didn't talk about heads/pistons. Stock heads aren't gonna get you there. If you can get some aluminum heads that flow well and get your compression to 10:1(ish) you'll have a little ripper. The lg4 in 84 had 8.4 (ish) compression. Idk how your gonna get to 300 hp w that bottom end unless you use better pistons.

another option is a mild cam, keep the lower compression, better flowing heads and a little supercharger. Im aware that this will be an unpopular suggestion.

the HO engines had 190hp and were pretty quick. So keep in mind 300hp is just a number. 300hp at 7k is useless. If you can get 350-380 ftlbs of torque you will be much happier.

 

The Engine Power episode (302 vs 305 shootout) used the stock heads and internals to make 302hp, 328 lb/ft. My engine is the L69, rather than the LG4, so it already has flat-top pistons and a compression ratio of 9.5:1.

When Engine Power upgraded the pistons flat-top design and added used Trick Flow heads, their numbers were 409HP and 388 lb/ft. So it certainly can be done, if I want to go that route with the extra parts.

And yes, you are completely right, torque is more important than HP in a regular street car, seeing as you are at lower RPM. The car had 240lb/ft at 3400 RPM

 

i missed the HO part of your post. I would use the comp cam, they make good stuff. If you have the better bottom end, yeah try the cam w some good headers. But, if the cam is coming out, your just a few hours of work away from a head swap!

Im in a similar situation w a 302 in a bronco. Ive been looking at all those 305/302 builds. I haven't had a small v8 since i pulled the 305 in my TA 25 yrs ago. Its kind of weird, theres so much available for the 302 performance wise. The 305 just doesn't get the same support.

Are the heads on the HO better flowing than the LG4 heads?

a set of dons headers to a 3in exhaust would be great for any combo.

 

From my understanding, the L69 and LG4 have the same head, it's just the pistons that are different. But again, I could be wrong.
Are there any specific heads you would suggest I read up on? I also have no idea what any head work may be needed with what I currently have, so it may be that it becomes more financially reasonable to replace the heads than get what I have decked and ported, if needed.

 

Are you ditching the ECM?...

 

Yes, ditching the ECM..I have a non-computer controlled dizzy and the Edelbrock carb is not ECU either. Definitely old school!

 

Oddly that was not even a F-car engine they used. It was a flat top 305 with 601 heads on it though.

 

I wish they would have started out with a F-body 1990 to 1992 SD LB9 and a 1990 to 1993 Fox-body Mustang 5.0L H.O. engine.

 

What they said they had in the 302 vs 305 was a 1990 Mustang 5.0 and an 84 "car"

"Ford 302 came from a 1990 model Mustang as a factory roller with a completely stock setup, save for a modest upgrade in the form of a Weiand Street Warrior four-barrel dual-plane manifold. The Chevy 305, sourced from a 1984 car featured a flat tappet setup with a similar aftermarket intake already installed. The goal was to get them running on the dyno to find out where each engine started on power, before giving them mild and affordable upgrades that were as similar as possible."

But you are 100% correct if they could have done a true f-body vs fox body head-to-head it would have been better

 

You could have the stocks head cleaned up or just get new ones. I don't know what heads work well on 305s. Part of what i was saying earlier was that the 302s have tons of support. There are tons of heads designed for them. I know you can use 350 heads on a 305 but its not ideal. If you our gonna do heads id reach out to some manufactures. Id also pick the brains of some of the guys on this board. I have fast burns and they're great. But probably not great for a 305. L98 heads would give you great compression and are decent flow. They're pretty inexpensive also.

 

Seems like the TFS heads that they used on the 305, during the 4th episode of the series, was good on a 305.

 

If the price difference between a Generic Melling cam or the like, and a Comp product, is "too much", or is even a point of serious consideration, then wasting money on 305-specific heads is even more off the table. As far as I can see that's a dead-end monkey-spank pipe dream.

Personally I'd run a Comp XE262 in your situation. Butt if you want a "cheeeeeeeeeeep" cam that works well enough in a 305, I'd suggest a Summit 1102. Since the price of everything has been officially lowered recently by diligent White House attention to "affordability", its price has decreased from about $100 a year or 2 ago, to something over $140 today; butt it's probably still the cheeeeeeeepest way to get a cam.

There's NO WAY IN HELL you're getting 300 HP at the wheels (360ish at the crank) out of a daily-driveable 305. No, the Melling cam won't give you that; no, the Comp won't either. That's raw unadulterated unvarnished unmitigated unalloyed FANTASY LAND and BULL PLOP. You're asking to take a motor that was "rated" FWIW at 190 HP at the crank, and essentially DOUBLING it with a cam and exhaust. Ain't happenin. Be realistic. Even 1 HP per cubic inch, with an old-skool simple carburetor, is TOUGH ENOUGH to get while maintaining acceptable fuel consumption and low-speed manners. Something in the neighborhood of 1.2 per CI is ... yeah. If you can get 225 to the wheels, you'll be lucky. HP isn't what makes a car fun to drive, anyway; since HP = RPM times torque AT THAT RPM times a constant, and the RPM has to be high to get a high HP number, it's the wrong thing to chase in a street car. About the most torque you can get at ANY RPM on pump premium is roughly 1¼ ft-lbs per CI, and even THAT is pretty tough. For "fun" street use you want peak torque to occur within a range of RPM that you'll actually be USING, say, the 3000s; having no torque whatsoever until the RPMs reach the stratosphere - which is what you have to do to get high HP #s, is sacrifice low-RPM efficiency and performance - is a recipe for having one of those all-bark no-bite wonders that sounds like a race car butt gets its a$$ handed to it at stop lights by soccer moms in minivans. Be realistic.

 

If only there was a motor that fit in exactly the same spot, but had more of that practical low end torque. Seems like another 45ci or so would be a huge benefit across the entire rpm range.

 

LOL !!! I was waiting for Sofa to chime in (and glad he did)...

 

I don't like the whole Ford 302 vs Chevy 305 Battle idea...

It should be a Ford 302 vs a Chevy 302 Battle!

The way that our Cylinder Heads/ Combustion Chambers are designed, the 4.00" Bore and 3.00" Stroke has a significant advantage unshrouding the Valves/ Chambers, compared to the 305 with the 3.736" Bore and 3.480" Stroke!

The ONLY way to try and help the 305, is to machine two large notches in all the Cylinder Walls (similar to the Mark-I "W-Series" Big Block Chevy Engine).

Otherwise it is not a fair fight!!!

 

I agree completely...

 

So the 302 in my bronco is a crate engine w 300hp and 325tq. Thats w 9:1 comp and a the nothing special steel heads. Its really nothing special spec wise. Its super low tech. This is my first experience owning an old ford and a 302. They are very different than a 305 power wise. It moves the 4000lb bronco pretty well. Before i actually drove it, I was planning to rip out the 302 for a 347/351. This plan was based on my experience w the 305s I've driven. I may have changed my tune. The 302 has much more power than I was expecting. Its an interesting little engine that I'm still learning about.

 

Sofaking is always so direct, sometimes jarring but wise nonetheless! It isn't a matter of affording a Comp cams vs Melling. It is a matter of if the extra cost was worth it or not. If the Melling and Comp will likely have the exact same results, why pay extra? But if Comp runs better, brings more low-end torque, or has better street manners, then I'll go that route.

And yes, I know the 350 can be better overall, but I have a 305 and I want to keep the 5.0 HO but actually make it a "high output"; it's more emotion than logic, but it's the path I'm taking. I just want to make wise purchasing decisions to build this engine out. And I'm sure some of you will say that none of this is wise, which may be true. But it's the path I'm going down, whether wise or not

 

Id do the comp cam and maybe port the heads, do some headers and call it a day. It will he fun to drive and faster than it is now. Maybe you have 250hp, maybe 300hp. Who cares, it will be fun. Keep it simple and enjoy it.

 

I think the comarison is valid; the odd-bore 305 is what we could buy in the day...not a Chev 302. So....that's what WE were comparing in the '80's and 90's. Valid.

And? The 305 compared quite favorably until episode 4. Even in episode 4 it did darn O.K.

 

Tom 400 CFI….Agreed.
Surprisingly, it seems the age-old trope of “The 305’s “the bore is too tiny to support high rpm HP compared to a 4.00” bore” is not valid, unless you throw a huge cam, compression, better flowing heads, & don’t mind an unstreetable engine that couldn’t pull a hat off the top of your head under 4000 RPM.

 

This statement is completely INCORRECT: "The 305’s bore is too tiny to support high rpm HP".
305 Engines can absolutely make power! We used to build TONs of them!
We have build 305s with proper Heads and Valve-Train that Rev past 11,000 RPM and make more than 700HP NA.

However, to REALLY have a competitive 305, meaning HP/ Cubic Inch...
Notch the Cylinders (David Vizard has proven this over and over again) Or...
It takes an Aftermarket Cylinder Head with a Chamber Designed small enough to unshroud the Valves to a similar ratio normally seen with a 350 or 400 Designed Chamber.

This happens now all the time with the 5.3L Gen-III/ IV SBC Engines as "Small Bore Chamber Cylinder Heads".

Any real Engine Builder would tell you that the Ford 302 vs Chevy 305 Competition is unfair...
And that with racing Cylinder Heads and Valve-Train, the Ford 302 would destroy the Chevy 305.
The 305 Only did well in this competition because the low performance Street Parts used are much better Designed for the Chevy Small Block over the Ford Windsor.

 

It is certainly not my goal to have an unstreetable car, so my focus on expected or desired HP was no bueno, rather than focusing on lower end torque, as this is not and will never be a racecar, but something that will bring a smile to the face.
Is there a reasonable goal for torque to keep the 305 peppy yet well mannered? Or just build it like I was going to and be happy with what I've got? It has always been my mantra that the day you don't learn something is a day you've wasted. You guys are continuing to remind and teach every time I reach out.

 

Well then, I stand corrected. 😉
So much for 40 years of lightweight car buff magazine spewing propaganda falsehoods!

 

Torque on pump gas w/o boost = 1.2 - 1.25 × CID, at its peak RPM, well-built, on pump gas; out of a 305, that means 350 - 360 or thereabouts, AT BEST, which will be 275 or so at the wheels, at some engine RPM or other, yet to be determined. Could be at 2000, could be at 3600, could be at 5500.

Pure and simple. It's a 305. That's what you get.

To get a "high HP" motor, you have to move the peak torque up high in the RPM range.

All you need to do now is, choose a cam, compression, and other supporting parts, that puts the peak torque RPM at a point where you can USE it. Some of those support parts are already chosen; your heads, your exhaust and your intake manifold for example. If you choose a cam that doesn't work WITH them, then neither the cam nor those other things can work their best. There's no "compensate for" anywhere in this. Either the parts cooperate or they fight each other. Best results occur when all the parts work together toward the same goal (goal being, the desired peak torque RPM range).

The higher the static compression (the mechanical ratio of cyl volume with the piston at BDC to the volume at TDC), the higher the peak torque, and the higher in RPM you can move the peak torque up to. Problem with excessive compression is, you HAVE TO use alot of cam, because if you don't, the compression will be SO high that it'll ping MERCILESSLY at lower RPMs. There's a kind of a "sweet spot", which is commonly referred to as the correct "dynamic compression ratio"; what it means is a combination of compression and cam that gives a DCR of something in the mid 8s, let's say 8.3 to 8.6 at most, which is high enough to have all the low end torque possible for the CID, yet low enough to run on pump gas. Look up the "calculators" for that on the Internet and you'll see what I mean about the balance of compression vs cam. Your static compression is already set in concrete by your heads and your pistons. All you can change now is the cam choice.

Do you ever drive your car with the engine at 6000 RPM? I'm guessing, no, except maybe once in awhile if you take it to the strip. Therefore you don't want "high HP" out of a small CID motor. That requires too much RPM. You'll end up with wimpy torque at lower RPM where the engine spends its whole life.

What RPM do you leave a stop light at, and then spend 99.999% of the time with the engine in a range from there? If you're anything like the rest of us, you probably have the clutch fully engaged at 1500 or so, you want to accelerate briskly as the RPM gets up past 2000, then shift in the high 2000s or low 3000s, recovering to 1800 - 2000 or so, repeat for next gear. When you're feeling spirited you probably wind it up to 3600 or maybe even 4000, and after shifting it recovers to 2500 - 3000 depending on which shift. Then you cruise down the street or highway anywhere from 2000 to 2500. No?

You want to build a motor that is at its best doing THAT. Big numbers on a dyno are WORTHLESS if they don't make your car do what YOU want to do with it. To me, that means peak torque needs to be at around 3600 or so, maybe as much as 4000. Anything beyond that, you'll never use.

That's what the XE262 does in a 305. That's why I recommend it. The Lunati Voodoo that's a half-step lower on paper than the XE262 is another excellent choice. A high compression 305 (L69) in front of the gear than you have (3.73) is enough motor for cams like that, and a lesser motor than the L69 such as the LG4, isn't enough motor (compression) for them. There's no such thing as "too much cam", there's only "not enough motor".

 

You are correct, this car will see every little time at 6000 rpm, and most of its life would be in the 1500-3000 rpm range, as you suggested. Therefore, 350hp at 6000 rpm is a complete waste and just ego, whereas 350lb-ft at 3000 rpm would be fun. I've watched several videos and read multiple articles on flat tappet vs roller cam. The Engine Power episode did a retro-fit roller, which made both the 302 and the 305 roller lifters. The XE262 is a flat tappet cam. In my application, knowing the lower RPM range to be used, is there a benefit of flat vs roller lifters here? Everyone seems to go roller lifers and roller rockers, but I'm not sure if it is hype or real in my application.

 

There's some benefit to power capability, very slight, to a roller cam.

Main benefit is not having to worry about the engine smoking itself.

To put a roller cam in a 201 block (the one used in the L69) which of course doesn't have the factory roller provisions because no features from the future, you'd need what's known nowadays as a "retrofit" roller cam, a set of link-bar hyd roller lifters, and a cam button. Price out the cam & lifters and you'll see why people are still willing to risk their motor eating itself with the old flat-tappet system. They generally also require better valve springs. Which incidentally, even if you go with a flat, MUST be replaced; and it's almost impossible to have "too much" valve spring, within reason. In 2026, I'd suggest LS6 ones or PAC 1218, with the Comp "adapter" retainers & hardware, set up at 1.800".

Roller rockers help out valve guide longevity by having the roller in their tip roll across the valve stem rather than slide; and they lower oil temp SUBSTANTIALLY. Look at a set of used stock rockers and notice how they're BLUE from the heat at the ball. The problem gets even worse when cams with more lift are used. All that heat goes straight into the oil. The oil also lasts longer without turning black because it's not constantly bathing literally red-hot moving parts. Roller rockers also have MUCH more consistent geometry than stock ones; a typical "1.5 ratio" stock rocker might ACTUALLY MEASURE anywhere from about 1.38 to 1.45 or so typically, with most of em MEASURING in the 1.43 neighborhood. Pathetic.

 

Though all 4 episodes/build levels? In one episode the 305 was handicapped by low compression...so IDK if that statement is true across all tests?

Either way, once again...these are the "lo-po street parts" that we, on the street are using, basically. When we go to the drag track, our 305 car will have some variation of these mods and parts....and the dude in the 'Stang in the lane next to us, will too. So whatever "hi-po not-street parts" could be used...we ain't got 'em.

 

Your head choice will be limited by valve size due to the smaller bore of the 305. Large valve heads Will NOT Work.

 

No idea, I didn't see much of it...

Low Static Compression Ratios can certainly hinder Power Potential as Dynamic Compression Ratios will most likely be abysmal.

 

Weird. O.K.

 

"Price out the cam & lifters and you'll see why people are still willing to risk their motor eating itself with the old flat-tappet system. They generally also require better valve springs. Which incidentally, even if you go with a flat, MUST be replaced; and it's almost impossible to have "too much" valve spring, within reason. In 2026, I'd suggest LS6 ones or PAC 1218, with the Comp "adapter" retainers & hardware, set up at 1.800"."

This leads to exactly what I was trying to ask. Is the cost of something like a roller cam set worth the extra cost, or would that money be better put to porting the heads or other mods for the 305 to meet my goals?

 

A roller conversion is totally worth it if the motor "eats itself" via a flat not breaking in. Id never instal a flat tappet cam at this point in my life. I feel this way for a lot of reasons. But billions of flat tappets have been installed and us roller snobs are just that. If there is a budget here then yeah, the money is better spent on air flow through the heads. If the budget permits then both ported/built heads and a roller. Its all about $

 

It's all about risk.

It's kinda like insurance... Do you need it? Is it "worth it"? How much should you pay for it?

If it's health insurance you're talking about, and you never get sick, then you could argue that you didn't need it. OTOH if you don't buy it and then you DO get sick, what then? How can you look into the future and know that? If it's car insurance, that's mostly liability coverage, which pays for bad things that happen as a result of you and your car; if your brakes fail and you run over a school bus full of kids, how much is that gonna cost? Will it be cheeeeeeper than buying insurance? If you buy insurance and never cause an accident - even something as simple as a 5 mph rear-ender on wet slick pavement at a stop light, or a parking lot dent - was it "worth it"?

Switching to a roller cam setup is like that. If you decide not to do it, what if a lobe eats itself and sheds metal chips into your motor and ruins it? What's the cost of fixing that? What's the likelihood? I can talk all day about the cost butt I can't predict whether it will happen. Flat-tappet cams were all we had for many a long year, and mostly worked fine; butt I've had more than one go flat in my own motors. Destroyed acoupla pretty good ones in fact. Long before the factories started converting to rollers. People still use em, and they still mostly work fine, butt they fail ALOT more often nowadays, even than they used to. It's definitely a risk.

I actually have a crystal ball. Unfortunately it's a bit murky when I look into it and ask it whether your particular motor will be lucky that way or not. Butt I will say that personally, I won't run a flat-tappet anymore; they've cost me too much over the years, and besides just the cost, there's all the labor that it incurs, and vehicle down time, if one fails. Butt everybody has to make that trade-off decision for themselves.

Budget is key here. It doesn't matter whether it's "worth it" in some way, if the funds aren't there to support it. After you looked up the prices of things, what did you think? Is there money in your budget to cover a roller conversion in case you decide it's "worth it"? Or is it an unattainable extravagance no matter what? Only you can answer that most basic question, even more basic than the ones about risk.

You can buy all the tools and supplies to port your heads yourself for less than $100. IMO that's DEFINITELY "worth it". Not least because it carries relatively little risk. The main risks in that are getting carried away and damaging them, or making their flow WORSE instead of BETTER, which is definitely possible.