Couple of 84 305 questions

[TheCrazzyOne]

After some issues with my 84 wagon (overheating mostly) im pulling and rebuilding the motor.

First question is: Stock is only 170 hp. If i decide to keep the 305 is there any heads I can buy to get around 250hp?.
Im replaceing pretty much everything in the motor..
Would it be worth it to keep the 305 or should I just get 350 block and build it?

Also looking at these crates on ebay, runing about 2,000 for 330hp. but not realy looking to spend that much, but I do realise that all new parts for a 305/350 could push about 2,000..

anyways, the wagon is a veary heavy car, wanting a motor that can pull it, aswell as any load I may be pulling with it IE: another car..

and any carb recomendations?, wanting decent amount of power with less consumption. currently has a quadrajunk on it...

and as a cosmetic question.. straight dual or side pipes?

[silicon212]

350 all the way. Wagons want torque, and when it comes to torque there's no substitute for cubic inches.

Also, the E4ME Quadrajet is the only carb you can use with the ECM - switching to something else entails replacing your distributor with one that has a vacuum advance as well as rewiring the TCC on your transmission. As for efficiency, if the car is underpowered, you'll find yourself getting better MPG with the 350 - also the Quadrajet is the most efficient 4-barrel you can get for that. When properly tuned, they're hard to beat (the Q-jet) - I've run all of them.

[Blue Bowtie]

If you keep the 305 (dished pistons and all) look for a pair of 14014416 heads. These are from 305s used in F-cars. Combustion chambers are only 58cc, and port flows are much better than earlier castings. Most had 1.84/1.50 valves, but can easily be machined for 1.94" intakes. The 1.84 valves are fine for most applications.

For a heavier vehicle, a higher stall torque converter is appropriate. The converters used in S-10 trucks with 4.3L V-6s have about a 2,100 RPM stall, as opposed to about 1,400 for your stock unit. You can get a reman from GM, with a warranty, for about $200. You'll get the same kind of highway mileage from teh TCC, but much more torque throughput at lower RPM, making in-town driving a lot more pleasant.

If you think the E4ME QuadraJet is "junk", you obviously haven't run a Holley or Carter knock-off in a street application lately. The only way you'll get better mileage than the Rochester (and more potential flow) is with an EFI system.

[silicon212]

Originally Posted by Blue Bowtie

If you keep the 305 (dished pistons and all) look for a pair of 14014416 heads. These are from 305s used in F-cars. Combustion chambers are only 58cc, and port flows are much better than earlier castings. Most had 1.84/1.50 valves, but can easily be machined for 1.94" intakes. The 1.84 valves are fine for most applications.

Question: How well would those 1.94's clear the cylinder bore, and would you have to machine reliefs into the bores to clear them? How bad would shrouding be? I'm just curious, because I've always wanted to see what a 305 would do if it could breathe. On those heads above, are the chambers 'open' or 'closed'?

[slavejay]

when replacing the torque converter with the one from the s10, is there any other changes that need to be made?

[silicon212]

Originally Posted by slavejay

when replacing the torque converter with the one from the s10, is there any other changes that need to be made?

Make sure you've got the right input shaft for it. Most 1984's, as well as all earlier ones, have a 27-spline input shaft in common with the TH2004R. Some late 1984s as well as all newer models have a 30-spline input shaft. The S10 TC requires the 30-spline shaft and if your transmission is factory, you will need to replace both the input shaft/drum and possibly the front pump to make it work.

If you put it all together with the wrong parts, in your case, you will find you have no drive and you'll have all sorts of noise from the front of the transmission, as well as a junk TC.

If you decide upon the S10 unit, you MUST make sure it's for the 4.3 V6 and not the 2.8.

[JunkyardLife]

Be sure to change the gears in the rear..Thatll help a huge amount with all that weight.
Q-jet is probaly best for gas mileage, but for simplicity Id go with a vacuum secondary Holley. If you want something more for racing, Id choose a Carter/Edelbrock with mechanical secondaries. For a mild build 600cfm will fit nicely. Youll lose bottom end power with too big of a carb.

[Blue Bowtie]

Si212,


14014416 heads are wedge chambered, not kidneyed like later SBC heads. By common definition, they are "closed" chanber since there is a quench area. In the '416 heads, 1.94" intakes will not experience bore interference, but shrouding can be an issue if the chamber is not clearanced a bit. Deck shrouding is seldom a problem unless the cam profile starts to get close to .500 net. This example shows '416s with 1.94 and a little flycutting on the chamber wall:




These are prepped with 1.94/1.50 valce and no serious shrouding:




As for the converter, the spline count and drive lug pattern needs to be matched to the transmission, as always.

Originally Posted by JunkyardLife

Be sure to change the gears in the rear..Thatll help a huge amount with all that weight.

Gears will help with acceleration, but can hurt highway mileage. A loose torque converter will also help with acceleration but will maintain highway mileage.

Q-jet is probaly best for gas mileage, but for simplicity Id go with a vacuum secondary Holley.

I'm not sure I'd call a single line Holley (like a 4150) "simple", especially when you consider you'll have to change the venturi pod for a more appropriate vacuum signal on the 305, rejet the primary and secondary, change the secondary diaphragm spring, tweak the accelerator pump, change power valves, and still have a compromised carburetor with no feedback to the ECM.

The "complicated" Rochester:




The "simple" Holley 4150:

If you want something more for racing, Id choose a Carter/Edelbrock with mechanical secondaries. For a mild build 600cfm will fit nicely. Youll lose bottom end power with too big of a carb.

If you want something more for racing, find a trailer and different vehicle to be towed behind the wagon. A 5,000 pound barge is not going to provide the best 60's and ETs, even if the trap speeds are up there.

The Q-Jet is capable of 780 SFCM in stock trim, even more if the secondary AV is altered, like on the BBC, Buick/Olds/Pontiac 455s, and Cadillac 472s and 500s. They flowed more like 840 SCFM, but only when needed - Unlike the Holley They flow equally well on a 283, but only up to the requirements of the engine. Ain't it cool?

[JunkyardLife]

This has just been my experience. Ive heard alot about how Q-jets are so great, but Ive never built one for myself. Its nice being able to go to Autozone and find performance parts for Holleys and Edelbrocks.

Id like to build one and give it a fair assessment. Next time I build a Chevy Ill do a Q-jet. I like the spreadbore design. Better throttle response.

Good luck

[TommySS]

I need to change the 305 in my wagon. I like the 350 GM offers, and it's all brand new.