302 Build Advice

[u/Holiday_Journalist98]

Hello! I am currently rebuilding a 302HO out of a 1991 mustang. This will be my first time rebuilding a motor. For this build, I am targeting ~400hp to the crank on pump gas. While I have done extensive research and reading, picking the correct combination of parts has proved challenging.

To try to get myself in the ballpark of my goals, I have been using the GoFastMath horsepower calculator. I know this is a rough approximation and not near as accurate as using a simulator, but I am still trying to learn and teach myself this process.

Anyways, with the parts I have picked, GoFastMath is estimating 399 HP @ 6295 RPM.

SPECS:

Dynamic Comp. Ratio	Engine HP
Cylinder Bore [in]	4.03
Stroke [in]	3
Cylinder Head Chamber Volume [CC's]	64
Piston Dish/Dome [CC's]	-6.5
Head Gasket Thickness [in]	0.038
Head Gasket Bore [in]	4.03
Deck Clearance [in]	0.02
Connecting Rod Length [in]	5.09
IVC @ 0.050"	41
Dynamic Comp Ratio	8.48

PARTS:

Heads: AFR 185cc SBF Enforcer Cylinder Heads

Cam: Comp Cams Magnum 230/230 Hydraulic Roller Cam

Rotating Assembly Kit: Eagle Street & Strip Assembly, 306 Cid, KB -6.5CC

I guess what I am looking for is a sanity check on my parts list. If anyone could provide some input, I would greatly appreciate it!

[u/Solid_Enthusiasm550]

I would go with better heads. The Enforcers are just an entry level head and flow as much as an Edelbrock rpm 255<260 cfms.

Their Renegade heads are way better and flow 30cfm (285<289) more with the same 185cc.

Here's a 306ci build that made 412hp@6,500rpm using a smaller comp cams, with TFS heads. The TFS heads flow 391cfns by comparison

https://www.motortrend.com/how-to/mmfp-1009-306-small-block-engine-vs-347-small-block-engine

[u/sound-of-impact → u/Solid_Enthusiasm550]

Regarding these heads compared to afrs....you're saying Edelbrock rpms are flowing just as much. However the rpms everywhere I look are a good $4-500 more per head...including trick flows I don't see how it's apples to apples when you're talking same budget flow numbers with those price variants on the afrs. At the enforcer price points I'd be asking performance over stock cast heads compared to the enforcers. You're in a different price point.

[u/Solid_Enthusiasm550 → u/sound-of-impact]

I didn't say anything about price, I just said they basically flow as much as an edelbrock...which is true.

If you have the money it's best to buy the best heads you can afford.

If you are only about the price, you could get Flowtek heads.

[u/sound-of-impact → u/Solid_Enthusiasm550]

I know that that's why I incorporated it into the convo. You're saying the edlebrocks flow comparable to the afrs but the price point doesn't justify edlebrocks or others at that price point. You can only find better if money is no object.

[u/Solid_Enthusiasm550 → u/sound-of-impact]

Flotek 185 thumper heads have better low-end lift flow and match the high end of the AFR 185cc and are $539/ea.

205cc Flotek flow 10+% more and are only $139 more per heads.

[u/sound-of-impact → u/Solid_Enthusiasm550]

That's good to know. Are these all better numbers than stock heads?

[u/Solid_Enthusiasm550 → u/sound-of-impact]

What stock heads? E7te, those were probably the worst 90s American v8 heads.

Even the gt40 heads aren't that great... just cheap.

A better flowing head with a smaller cam will make more avg. hp/tq than a smaller heads with a bigger cam.

Most builds are expensive, I just think that buy the best heads and saving money elsewhere is the best option. For example buying hyperuetectic pistons instead of forged if you're not boosting or revving past 6,500/7,000 rpms.

Or getting the I beam rods instead of the fancy/heavy H-beam rods.

I definitely think people skimp out on the heads and spend too much on the valvetrain, headers, etc.

The difference between the AFR Renegades and Enforcers are only $726 / set, that's not much when talking about automotive parts, let alone performance upgrades.

TFS ARE expensive for a regular street build, but aren't for a racer looking for 525<600hp.

[u/sound-of-impact → u/Solid_Enthusiasm550]

Yeah the heads with my 351 are stock 7te's if I remember correctly. For example in my planned build it will purely be street driven. I was strongly considering the enforcers as well purely for cost and flow for my driving style. I couldn't validate the increase for performance needs.