Will this produce the results I want

[Swearbody]

I want 300whp and 350wtq. Its not for a hotrod but the 305 in the truck has to go!!

4 bolt goodwrench block with stock rotating assembly
Comp xe262 cam and lifters
Summit 007 72cc 2.02intake 1.60ex heads with comp 1.6 roller rockers,guide plates,screw in studs, comp springs, etc
performer rpm air gap
1906 av2 carb
summit hei distributor with medium springs and adjustable vac advance
summit stainless headers and a 2.25 exhaust kit


If not oh well because the parts already here.

 

[Taylorb27]

I'd say you'd be a touch more than 300 tire. Tbh though don't get hung up on numbers.
You are literally doubling (if not more) power switching from your 305 to the engine you have planned.
Not sure what pistons are used in the goodwrench motors but you should have a good cheap pump gas runner that will do burnouts for days and haul you around town

 

[Swearbody]

The Goodwrench block I have is the one that claims it can make 260hp with a 4 barrel and dual exhaust. It has 8.5:1 compression with the 76cc heads so i think the pistons are around 8cc relief dishes. It should with my 72cc heads be closer to 9:1 comp or there about. The cam i picked is much more aggressive than the stock goodwrench cam thats for sure and should be a great fit with the new parts. With that,the intake,heads,etc Im confident It will out-rite demolish the worn out 36 year old 305...regardless of numbers I agree.
So I could still use 87 gas...thats great. I was planning to use 91-93 and maybe run a little more timing but ive been told that power gains are not worth the increased cost of the fuel and that that cooling the engine(im in alabama) may become a problem on hot days with the increased timing.
I still plan to run a medium spring in my distributor so it will have a little more aggressive ramp in but nothing drastic.

 

[shiftpro]

If you haven't bolted the heads down yet, run a piston up to TDC. See how far down the hole the piston sits. I bet the deck height is on the tall side. I mean like the piston will not be flush with the top of the deck, like not even close. If the piston is sitting way down in the bore it will be difficult to get that compression you so dearly need.
But what do I know? I'm a high compression junky. That's why I run propane and 11.1 yeehaw!

 

[Swearbody]

If you haven't bolted the heads down yet, run a piston up to TDC. See how far down the hole the piston sits. I bet the deck height is on the tall side. I mean like the piston will not be flush with the top of the deck, like not even close. If the piston is sitting way down in the bore it will be difficult to get that compression you so dearly need.
But what do I know? I'm a high compression junky. That's why I run propane and 11.1 yeehaw!

The pistons have reliefs for the valves but im not sure of the deck height vs top of piston. The heads are on already. It was blueprinted at 8.5:1 before the decrease in combustion chamber volume from 76 to 72cc but i do not know how much the heads were decked when I took it to the machine shop. I had the heads already so i just had them decked and worked for the new studs,springs and rocker setup. Im assuming at least close to 9:1
I want it to be a reliable truck for years to come and think any more than 300whp 350tq is gonna beat the rest of the truck to hell. I want to build a 11:1 comp big block and slap it in a camaro/firebird but thats for another day....waaay down the road. I have to finish the truck and also have an ep3 civic coming soon that im turboing and shooting for 400whp on.

I have buddy running propane setup on his Jeep 2.54cyl and he loves the **** out of it.

 

[legopnuematic]

If you haven't bolted the heads down yet, run a piston up to TDC. See how far down the hole the piston sits. I bet the deck height is on the tall side. I mean like the piston will not be flush with the top of the deck, like not even close. If the piston is sitting way down in the bore it will be difficult to get that compression you so dearly need.
But what do I know? I'm a high compression junky. That's why I run propane and 11.1 yeehaw!

X2, Thats the way the re builders pistons in my 76's 350 are, they are a shorter compression height and put them WAyyyy down in the holes. Like big enough to park a bus in there. Which is why I am using the thinnest head gaskets that felpro sells to make up for the **** deck height.

 

[Vbb199]

Those are some pretty good sized valves.

Bigger than stock cast iron vortec everyone including myself favors, just a little bigger chamber than vortec (64cc)
What size runners do those heads have?

That combination seems like it would bring you up to 9:1,but that also depends on your deck height.

Like shiftpro said, may wanna bring a cyl up to TDC, and take depth micrometers and check to see how deep the slug sits before you make a move on heads.

That deck height will kinda determine what you can get away with.

I vote keep it on pump gas, not exceeding 10-10.5:1 c/r

(some argue on what octane to run, but I haven't had spark knock issues on 10.5:1 on 93 octane except under a heavy load like romping down and pulling a trailer WITH timing turned up a couple degrees)

You mentioned comp springs, as long as they're stout enough so as to prevent valve float you'll be fine, all really depends on cam, but I like to wind my small blocks up.


@RedBeard_83 yoi may wanna follow this if he goes thru.

 

[Catbox]

These are the heads he is using...
https://www.summitracing.com/parts/sum-152123

Here is his camshaft...
https://www.compcams.com/xe262h

I would say it will be a champ with how you have it.
I read that the block and heads are already assembled and ready to go.

Assuming that you simply reused the pistons that came in the block and did not change anything other than the heads, you should have slightly more compression.
Unless you used a thicker head gasket to reduce the compression.
It is a give and take kind of thing.

This engine calculator is a nifty little tool.
There are a number of types out there that do different things too.
https://speedmaster79.com/tools/engine-compression-ratio

Here are a couple of ****** guess's that I made assuming stuff about your engine.
Of course it will probably be a bit different, but you can see the difference with a different head gasket in there.

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[Swearbody]

165cc intake runners https://www.summitracing.com/parts/sum-152123

I really appreciate the input. My thinking is that since the motor had 8.5:1 with the smog heads that the 007 will in fact increase compression a little since the combustion chamber is 4cc less. Unless im missing the point on this. Nothing was changed on the block...so wouldnt a smaller c chmb lead to higher comp.

The springs are just a single setup recommended by comp with the cam. Im not revving it out past 6k ever by choice. I have other toys for that(honda @ 9k-rpm+)

I ran a thin gasket as well .020 if i remember..ill have to look at my parts list. Also the heads have been decked but I dont know how much and probably as little as possible since i only told them to true them up. The heads came off an 82 I had that ran gobs of nos so I thought it best to have them pressure tested and decked before i reused them.

I just want a little pep and the ability to safely pull a loaded 18ft steel car trailer.

I would take the heads off and check deck height and such however I just dont feel like I need to.
Why? In this case Im confident that whatever I end up with will be close to 9:1 and that was my goal. I wouldnt change anything regardless of what I discovered so why waste the $ and time.I mean I get what you guys are saying and I totally defer to your knowledge but its not that important to me since im building a daily and not going for maximum efficiency and hp.
Do you agree?

I would have purchased a set of vortecs and had the screw in studs,porting,springs for more lift etc if i didnt have the 007s already.

The 007s also has a three angle valve job when produced. Dont really know that matters in this case but thought it was notable. The heads as produced would handle .520 lift and im running .512 with stiffer springs,roller rockers,and guide plates so 6000rpm shouldnt be an issue.


Anywho You guys rock. Keep it coming and thanks!!

 

[Swearbody]

WHen first starting this project The guys at comp and I came up with 8.7x:1 compression using a similar calculator with .040 gasket. They claimed to "know" the deck height for the goodwrench block but I wasnt at the time paying much attention. I used a .020 gasket if memory serves me so your calculations are dead ass on. depending on how much they took off the heads it may be a true 9:1

 

[Swearbody]

So the .020 possible difference in piston height from re builder pistons will give a difference in compression as mentioned. Its my understanding that a few 10ths of compression will not drastically change anything on this particular build. It should still have adequate quench-correct? I will still be able to run pump gas and have adequate compression to make 300+hp without revving it out to redline.
If im missing the point please intervene!!!

 

[Catbox]

I think you are on the good track to do all that you want it.
You will not really notice the minor compression change.

 

[Ricko1966]

In a perfect world you want quench at .040 so .020 is a ton if we are talking quench. I'm betting that your pistons park so far down the hole that no matter what gasket you use you won't get .040 that being said most people( I am not most people) live with whatever they end up with as long as the compression isn't to high. You're other choice is assemble the shortblock check the deck height and have the block decked and squared.

 

[Ricko1966]

Never done this on an SBC and not going to the shop to look at combustion chambers and pistons right now.In the past I have taken a long piece of thick plumbers solder run it through the plug hole and turned the motor by hand then took the crushed solder and mic'd it.It won't be perfect due to piston rock but you"'ll get a pretty close estimate.Look at a head you have laying around see if it's feasable to sneak a piece of solder in hold it and still be able to pull it out.As memory is coming back I think this was on a hemi I was building about 1994 or so.You may not be able to do this on an SBC, but I'd sure at least take a hard look.

 

[peats]

i think you will have a hard time getting 350 ft/lb torque out of that combo. also what is the gear ratio? the right engine with the wrong gears will fall flat on it's face