I'd appreciate your opinion on the following questions:

If I were going to replace the LG4 in my 85 IROC 5-speed with a brand new 305, is there a particular motor year that would provide a bit more Hp but still allow the carb?

If I were going to use the S/R torquer heads, what cam would you recommend?

Concerning exhaust: I'm currently using the L69/L98 manifolds, y-pipe and a cat back system, so I could stay with that; I could use the appropriate headers and y-pipe with hi-flow cat, etc.; or, I assume, I could use the dual cat set-up as in the ZZ4 conversion. Advice?

JamesC

 

well i'm not five7 and i sure ain't as smart as he is, but why would you want to keep the 305 considering the expense would basically be the same and you'd have lot more power.

 

I've very seriously considered the ZZ4 conversion kit, but I've decided against for the following reasons: octane, possible emissions difficulties since I have a T5--a non-world class that would no doubt require replacement with something like a T56 or Tremec--and finally, of course, overall costs.

A 305 can make decent power if parts are judiciously chosen--especially for an old fart like me who likes third and fourth on the highway--and I wouldn't have to mess with the transmission. The difference in expense between the 305 and ZZ4 is considerable.

That said, how about the 350 Goodwrench? Any experience?

JamesC

 

yes, but a 350 could be made emissions legal, so long as it is proper tune, with "judiciously chosen parts" and still make serious power.

go with the S/R torquer heads, a smallish cam, like the summit cam 204&214W/.422&.444 lift, keep the EGR,and keep the Quadrajet carb, and put a Edelbrock Performer cam.

Those parts are generally emmisons legal.

if you fail emmisions, there are ways to beat it, such as adding a gallon or 2 of racing alcohol to a tank of gas, as alcohol burns super clean. there are also other ways, which I am not familiar with.

 

well if you're going to be happy with the 305 the go for it ,i always wanted to play around with one since mose people trash them. my son had a strong 305 in a 88sc but he wanted "more power" so i built him a 355 that came out at 445 on desk top dyno, for what that's worth.

i run a little more cam and a weiand intake, holley carb, aftermarket heads w/smallest chambers i could get, and dished pistons

 

As far as 305s go, the '85 version is as good a base as any - flat top pistons, knock sensor. Building an emissions-legal version around that system is fairly simple.

The L69 exhaust is as good as you can get with cast iron manifolds. If you have performance heads, make sure the manifold ports are at least as large as the head ports - a little larger is even better. Dual cats is another step up, but a single 3" cat behind shorties with 2-1/2" down-pipes to 3" y-pipe would be more than adequate for a 305.

Dual-snorkel air cleaner is a must. For emissions-legality, a factory set-up is required, or a fabricated dual snorkel like in the tech article. The Ram Air dual snorkel would be trick, but wouldn't have the required thermovac. The single-snorkel LG4 air cleaner, though, just has to go.

I like the World heads; bowl clean-up is really needed, though. I didn't run them out-of-the-box, but just looking at them, I wouldn't recommend it. I'd include trimming the guides down as part of the bowl work. I went the full Standard Abrasives guidelines porting and polishing route because I intended to run the ZZ4 cam (which didn't work out - another story).

To keep the computer happy, use a computer-compatible cam. Mine has yet to complain after 5k miles of daily driving. I went with the biggest one Crane had in flat-tappet variety; if you stay with manifolds, I'd think the 2040 would be all the exhaust would support (although the 2050 would probably be fine, too).

I have a Goodwrench engine in my full-size, horse-trailer-towing van, but I've heard of people building them up (have seen a magazine article or two as well). The big limitation seems to be the heads and cam. I think they sell that as a shortblock, onto which you could put S/R Torquer heads & a good cam. With all the supporting cast, emissions shouldn't be any problem at all. I'm seriously considering the L31 shortblock under the rest of my current mods if funds ever become available (of course, it costs as much as the full Goodwrench engine...).

A healthy 305 in front of a T5 is probably a better idea than a equally-powered 350 because of the additional torque of the larger engine. But, the T5 could easily be lunched by either one with the appropriate level of abuse.

With the exception of the transmission, you're basically looking at mods like the "My Generation Camaro" articles in Chevy High Performance mag. In my opinion, the mistakes they made were: Edelbrock intake manifold and headers, too small of a cat (which they admitted), too small of a cam (which they never admitted), too little porting of the World heads (they were trying to limit it to the typical do-it-yourselfer's abilities). And, they stuck with the stock stall torque converter, which doesn't apply to you.

Quote:(originally posted by ede)
i'm not five7 and i sure ain't as smart as he is
Right......