alicat

Hi all, I haven't posted in a while.
I am looking at getting these heads, Trick flow super 23, 175cc heads, p/n TFS-30310003 Just wondering if the following camshaft kit, manifold and rockers that I am also looking at will work well. Considering that this will be on a 305 LG4 engine and street use only. What cam , intake manifold, and rockers would be suitable. I've searched and found info mentioning some of these parts in various posts, but just wondering what people thought of this combo, or can suggest other combos for a top end upgrade

These are the parts that I'm looking at to go with the heads.
Comp cams, SK12-238-2, cam, lifters and timing gear.
Edelbrock performer rpm manifold, p/n 7104
Trick flow 1.5 ratio roller rockers, p/n, TFS-314005-10
I've already done a free flowing exhaust, and changed to non computerised configuration, and running the mechanical Qjet. My engine is in good condition, and just looking to upgrade the top end for more hp, rather than buying a crate engine or similar. I'm in Australia so replacement engines are not cheap at all, even for something basic. All suggestions on alternative parts and products welcome. Id also like to keep the mechanical Qjet, but not sure how this would work with the trick flow heads.

Thanks for your help.
Cheers, Alicat.

BadSS

The Q-jet will work fine with the 7104 intake and the TFS heads.

The part number on the heads you listed are for a hydraulic roller cam. The flat tappet heads are TFS-30310001
https://www.summitracing.com/parts/tfs-30310001

That's a chunk of change ($1,480 US) for a set of "305 heads", but there really isn't anything else that will perform any better on the 305. A buddy of mine built a 305 with those heads for a hydraulic roller and he is very happy with it. He stuck with the computer carb and went with a 210/218-113 hydraulic roller (.560/.550 lift w/1.6 rockers). He shifts it at 6200 rpm with a modified stock intake - pulls over 17" vacuum at a 700rpm idle speed. He's not a racer and doesn't really care how much power it makes, he just wanted more. So, he hasn't had it on the drag strip or dyno or I'd give you some numbers.

You're better off, money-wise, buying the cam and lifter kit and going with a Cloyes true double roller.

To keep the shift points reasonable with the 305, the 7104 RPM intake, and those heads, I'd go one step down on the cam you listed to the 212/218-110, lift.447/.454 - $282.95
https://www.summitracing.com/parts/cca-cl12-234-2

Or if you want a little smoother idle and pull a little more vacuum, you could go with the 210/218-111, lift .447/.462 - $281.95
https://www.summitracing.com/parts/cca-cl12-235-2

The Cloyes "true double roller" chain, C-3023X (opposed to the non-roller in the SK Comp kit), is $27.99
https://www.summitracing.com/parts/clo-c-3023x

I'd also go with 1.6 rockers to get the lift up higher to take advantage of the higher lift head flow (.477/.484). The Comps below are full rollers and "good enough" for your spring pressures and will save you a few bucks - $237.95
https://www.summitracing.com/parts/cca-17002-16

I've never been partial of the steel shim gaskets for a "rebuild", so he used a set of Mahle 5746, .026" graphite head gaskets to keep quench reasonable and to keep as much compression as possible without decking or surfacing the block. $19.59 x 2
https://www.summitracing.com/parts/mah-5746

Other than that, everything looks good.

alicat

Hi Bad SS,
Firstly thanks so much for your great answer. Lots of good information there, and good pickup on the part number for the heads. I missed that one.

You are right about the heads being expensive, along with everything else. Those and the other parts I listed, plus shipping and tax and duty, and also the current exchange rate, put the cost around $4900 AUD. Unfortunately being here in Australia, that's how it is. Also parts stocked here are ridiculous prices,
with one place advertising those heads for $2400 AUD each.

As for crate engines, that's expensive as well. I did look at a 355ci blueprint engine with fairly generic parts, which has mixed reviews, and that is just under 10k, with others with better builds are upwards from there.

I presume that my LG4 is original as it had all the correct factory emissions gear on it when I bought the car, but that was all removed later. Runs well and pulls 20 inches off vacuum at idle, which hopefully suggests that it's reasonably healthy, and ok to upgrade the top end. As I said, it's just a cruising car, and nothing else, but would be nice to have a bit more go.

Thanks again for your reply, and the links. I'll have a look at the parts, and if you think of anything else let me know.
Cheers, Alicat.

BadSS

I’m not sure of the availability of used Vortec heads for you, but if you’re just wanting some extra power and not really trying to get all you can out of it, a set of Vortec heads and a vortec qjet dual plane intake (since you would be buying another intake anyway) is a really good bang for the buck combo.

If used, I’d want to get them magna-fluxed and surfaced. While it’s a good idea to upgrade the springs, if budget is a concern and you can snag a lower mileage set, you could reuse the springs and just run a set of good long slot 1.5 stamped steel rocker arms. If you go that route, go with the 212/218-110, lift.447/.454 cam to keep from having to swap springs and retainers.

alicat

That's an option, but there's not a lot of secondhand parts where I am in Tasmania. Possibly more on the mainland, but then I'm buying sight unseen without travelling.

I don't mind the expense so much, as long as the outlay is worth the gains. Shipping, taxes, and ultimately the currency exchange rate is what hurts.

I'll keep researching, but the parts that you have suggested seem like a good combo. Any suggestions for push rods, as it would be good to replace those as well.
​​
Cheers, Alicat.

Fast355

iTrader: (2)

If I were on your side of the pond, I would have a hard time not swapping a Holden 308 into the car. They should be about as common there as the 350 is here. I have seen some budget, stroked 308s make really nice power.

alicat

That's a valid point, although I've never been a Holden fan, and it's ironic as over here, a lot of people and families are either, Holden or Ford fans,
much the same as, Chev and Pontiac over there. Unfortunately for me, I'm not a fan of either, but I've always liked the American cars.

So preferably I'd like to keep a chevy engine in it, but obviously that will cost me more. Did you have any suggestions on pushrods, or are they much the same between brands. Thanks again for your help.

Cheers, Alicat

BadSS

Chances are you will need a different length than stock. You'll need to get a pushrod length checker to be sure - pushrods should be the last engine part you buy.

You will need a set of heat treated pushrods to run with the guide plates. I prefer using one-piece pushrods with a minimum .080" wall thickness. However, that's probably over-kill for your build. A heat treated 3-peice set of 5/16" diameter and 0.065 wall thickness should be OK with the TFS hydraulic flat-tappet springs you'll be running. I've used the Comp High-Energy pushrods on some hydraulic cam budget builds and I'm not aware of any of those builds having issues.