Re: 305 Builds

by Roadcaptain S3 Mon Feb 13, 2017 8:04 pm

Let me summarize for you, Damon.
46000 mile original engine.
383 sitting in corner of shop.
Challenge.
Something different.
Not in need of 500 hp.
Fun.

Bonus:
Looks on faces of fat old men critics who make "smog motor" and "boat anchor" comments as I throw burnt rubber all over them, their lawn ornament "muscle cars" and their lawn chairs.

Even if we build the 383, I'd still paint it corporate blue and make it look as stock as possible. Just for the bonus. Twisted Evil

by Limey SE Mon Feb 13, 2017 9:15 pm

I am right along with you Captain, ONLY I mean ONLY cash I would spend is for the Cam at /lifters (around 150 bucks) & trick flow heads @$599 which are Bolt and go for a 305 BTW

I have everything else Needed for the 359Hp version of the 305 and thats Under 750 Bucks in my Case

Cheapest crate right now with free shipping from Jegs is $1599 and Only at best 290 hp as quoted by them

by bracketchev1221 Mon Feb 13, 2017 10:17 pm

That's probably 599 per head. Not per pair.

by Roadcaptain S3 Mon Feb 13, 2017 10:25 pm

Right Limey,.
Then add all of the incidentals that you either HAVE to replace or SHOULD replace, fly wheel,starter, balancer, distributor, plugs, wires, intake,new motor mounts, carb water pump, fuel pump, gaskets and on and on. You should seriously consider replacing or upgrading the radiator as well, right?

Or get the package(s) that has all that stuff for $3000-$4000.And you still get 260-290 HP.
You want more power? On a crate, power goes up, price goes up too.

Lots of folks say "just throw in a crate engine".
I did it with the Laguna.
It was the Goodwrench 260 horse. At the time, the engine was $1100. We installed it in my friends shop. Before it was over, I had around 3k in it to do it right, not counting upgraded exhaust, which was another $800ish, IIRC.
Everybody hears "throw in a crate", and thinks it's way cheap.
It ain't, even if you do it all yourself.
I guess you could do it using old stuff you had laying around, but it would probably void the warranty and I sure as hell wouldn't recommend it.

So if it's done right and we are realistic about it, there's a big difference in price in "dropping in a crate" and adding some bolt ons.

Math?

Let's say all new parts from Summit. $1100 for Trick Flow assembled heads, $600 for carb and intake, $140 for cam, gaskets $25.
Maybe upgrade ignition, maybe not.

Really rough numbers, but I'd bet I'm fairly close.
$1865 vs. $3,500ish. Both for 250-300 HP. Hmmmmmmm?

by Roadcaptain S3 Mon Feb 13, 2017 10:29 pm

Damon23 wrote:For the money I don't know why anyone would build a 305 when you can buy a create motor cheaper. Unless you wanted numbers matching or for the fun of it. Either way you go you'll have a good reliable motor.

See above.

by Limey SE Tue Feb 14, 2017 12:22 am

bracketchev1221 wrote:That's probably 599 per head. Not per pair.

Dang you were correct Bracket LOL I did Find a Better Option for $795 a Pair for Patriots Have you heard about or dealt with them ?? Cam is 62 bucks Lifters prob another 50 or so Still Cheaper than Just the Price of Crate motor. this is what you Get for 1599 Btw
Then Add up all the Other schtuff you have to Buy

305 Builds - Page 2 Nal-10067353_sn_xl

by Damon23 Tue Feb 14, 2017 8:27 am

Roadcaptain S3 wrote:
Damon23 wrote:For the money I don't know why anyone would build a 305 when you can buy a create motor cheaper. Unless you wanted numbers matching or for the fun of it. Either way you go you'll have a good reliable motor.

See above.

I did see your post above. Did you see the last two sentences I wrote? Personally for the money I would buy the crate and be done but that is just me. I understand what you are trying to do. And for the $1599 you can throw pretty much all the accessories you have on the crate so I don't know what extra stuff is needed. I also look at it as more of a reliability with a warranty too. I could car less about 10-20 hp here and there. But I'm no racer and as well as my car with 145hp gets around I'm sure double that would be enough for me to get down road. Good luck with your project. Either way you go it should end up cool. Build your car for you and not the internet or for old men at car shows.

by bracketchev1221 Tue Feb 14, 2017 8:38 am

I think Patriot heads went out of business. They were bought out by Promaxx. They are not bad heads from what I have seen, but you do not want large runners. The trick flow head is only 175 cc. The Promaxx is 180-185, and you want a small combustion chamber. You need to keep compression up with aluminum heads to counter heat loss. So generally 1 number over a steel head is a good start. The trick flow heads give a 56 cc chamber to help with compression. I am not sure what the factory 305 heads are for a mid 70's car. I have seen head listings at 62 cc and 76 cc for a 305. You would have to see what heads are on the engine now. But figure the engine is probably 8.5:1 compression as it sits.

by bracketchev1221 Tue Feb 14, 2017 9:00 am

Summit does sell a set of 62 cc heads with 170 runners that could work. I don't know who is making the summit heads. I'm not crazy about the 2.02 valve in a 305 though. The heads seem more like an upgrade for a bone stock 350 engine.

by bracketchev1221 Tue Feb 14, 2017 9:32 am

The XE262H-10 comp cam is good, the XE 268 is going to be pushing it in a little engine. Lunati has the 10120701 cam and again, the 10120702 is a little bigger, not as bad as the comp 268 so it may be a possibility.

by Tom77 Tue Feb 14, 2017 10:51 am

Years ago I bought a 350 series one engine from autozone balanced and printed threw a small cam in it and beat the daylights out of it for years at the local dirt track. After that it spent some time in the Malibu till the 383 came along. Engine never let me down even after all the hot Arizona nights on the oval. Think I bought it for around $1500.

by brownbomber77 Tue Feb 14, 2017 4:38 pm

I've got a Comp Cam that is perfect for the 305....new...still in da box. Even got an Edelbrock intake for it, too....hell...it's a whole motor AND 700R4!!! TAKE IT!!! TAKE IT!!!

by pila Tue Feb 14, 2017 8:59 pm

Years ago I used the Comp Cams HE252 in the 305 engines, to get just a bit more power, and it did wake a 305 up a bit. Put one in a friend's boat with the 305, and it did get a skier up on the water better.....

by chevellelaguna Tue Feb 14, 2017 9:29 pm

I've been reading along and am all for a 305 build! Sure you can buy a crate motor, but like you said... To be able to shut everyone up with a little 3-oh-5, that'd be cool! I agree with Ray about the 262 cam. An iron head of 62cc would produce a noticeable amount of torque. I had 461 (if I recall correctly about the number) castings on an old 350 and it made impressive torque. If you have a low mileage 305 anyhow, I bet it's not worn out to begin with, I'd mic the bores clean them with a bottle brush hone, file the rings to the bore, re ring the Pistons. Wouldn't mess with the rods. Mic the crank, new main and cam bearings. You'd be good to go for at least another 50,000 torque shredding miles! You'll need new heads.... Be cheaper than rebuilding yours. Some dart iron eagle heads for $600 a pair, bare. Be a fun little motor!

by Limey SE Tue Feb 14, 2017 10:48 pm

Ok Guys with the Build does it have to Be a RPM Manifold that seems like alot of Mani for a 305

by bracketchev1221 Wed Feb 15, 2017 7:30 am

I would use the Performer EPS manifold.

by dynchel Wed Feb 15, 2017 11:34 am

The 305 heads I have have are. 58cc. They were pulled from a '84 Monte Carlo, it even had a aluminum intake marked GM cfm.

by bracketchev1221 Wed Feb 15, 2017 3:54 pm

dynchel wrote:The 305 heads I have have are. 58cc. They were pulled from a '84 Monte Carlo, it even had a aluminum intake marked GM cfm.

If your engine had 76 cc heads, the drop to 58 is where the performance gain came from. On your engine, basing off of an 8.5:1 compression, without changing anything else, the chamber makes it 10.25:1 compression. If the 305's in question use the 76 cc heads, they can see a similar gain. If they are 58-62 already, they are going to need a similar or smaller head just to keep compression the same.

by 73ss Wed Feb 15, 2017 6:30 pm

dynchel wrote:The 305 heads I have have are. 58cc. They were pulled from a '84 Monte Carlo, it even had a aluminum intake marked GM cfm.

If you can, measure the intake. If it's a 1.84, You've most likely got a set of HO heads. HO motors got 9 maybe 9.5 CR, up from the standard 8-8.5:1. Was the Monte an SS? "G" in the vin is HO. Those heads would give mom's camaro you mentioned earlier a good 20-25 horse bump. Most of GM's lineup got an aluminum intake in 80's to shed weight. They are not a bad piece. The 76cc heads would not have come on a 305. Small bore, small chamber. Most of the aftermarket heads listed in the above articles are 305 specific. I think it was the world heads had altered valve angles to clear the small bore. On the flip side, Guys have put 305 heads on a 350, Cheap way to build some good compression, but at the cost of a small intake valve.

by dynchel Wed Feb 15, 2017 7:39 pm

73ss wrote:
dynchel wrote:The 305 heads I have have are. 58cc. They were pulled from a '84 Monte Carlo, it even had a aluminum intake marked GM cfm.

If you can, measure the intake. If it's a 1.84, You've most likely got a set of HO heads. HO motors got 9 maybe 9.5 CR, up from the standard 8-8.5:1. Was the Monte an SS? "G" in the vin is HO. Those heads would give mom's camaro you mentioned earlier a good 20-25 horse bump. Most of GM's lineup got an aluminum intake in 80's to shed weight. They are not a bad piece. The 76cc heads would not have come on a 305. Small bore, small chamber. Most of the aftermarket heads listed in the above articles are 305 specific. I think it was the world heads had altered valve angles to clear the small bore. On the flip side, Guys have put 305 heads on a 350, Cheap way to build some good compression, but at the cost of a small intake valve.

They are the h/o heads. Last three numbers being #416. It was not a SS, maybe a LS? I had them gone through, a valve replaced, and the valves ground. They really woke up my 350 (had '76 cc smoggers) I believe the valves were 1.88

by pila Wed Feb 15, 2017 9:00 pm

I gave a 305 away to my nephew a couple months back. It had a Lunati cam & ran good, but I wanted it out of the shop !

by Limey SE Wed Feb 15, 2017 9:50 pm

ROADCAPTAIN I have worked a deal for the 305ho Heads so this is going to Happen

by ant7377 Wed Feb 15, 2017 10:14 pm

My buddy built a cheap 350 for his Camaro the local machine shop had a set of those on the shelf all done 300 bucks. Call around you might get a set like that too.

by Limey SE Wed Feb 15, 2017 10:19 pm

found a set Bolt and Go for 50 bucks from a Trusted friend

by Roadcaptain S3 Wed Feb 15, 2017 10:24 pm

I'm working on it. Gathering wisdom and a parts list.

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