have 84 Z-28 305HO, 700R4, original owner - has anyone installed the 305 stroker kit for 335ci, that I see advertised? have read all the arguments and blather abut "305 is junk, go to a 350", but I would really like to consider keeping the original engine in my baby - would go to 10:1 compression, balance, add Torquer heads 58cc, headers - this is basically a good highway cruiser, not for the strip. your thoughts, especially from anyone with first hand experience on this? ..... thx, bob y

 

https://www.thirdgen.org/techbb2/sho...hreadid=274223

https://www.thirdgen.org/techbb2/sho...hreadid=261308

https://www.thirdgen.org/techbb2/sho...hreadid=233667

https://www.thirdgen.org/techbb2/sho...hreadid=245224

https://www.thirdgen.org/techbb2/sho...hreadid=209198

https://www.thirdgen.org/techbb2/sho...hreadid=179128

If you want to keep it original, there are cheaper ways to get it faster. Also SR's aren't very good heads for power.

 

Care to expound on that?

 

s/r heads are actually pretty good heads for the 305. but a 4" motor is sounding more and more appealing....

 

As the original reply was saying (along with the linked threads - I didn't bother reading them all again), the increase in horsepower realized by the stroker kit has very little to do with the stroker kit. It's primarily due to the cam and heads that were put in/on at the same time.

I can understand being the original owner why you're tempted to keep the original engine in there. But, think about it - with different heads, different crank (and therefore damper), different exhaust - what is "original" about that? As is stated in a similar thread, if you want to keep the original engine, keep it in the corner of the garage.

However, you can wake up the engine with head porting (original heads, even), cam, and exhaust. That will get you 95% of what the stroker kit obtained (when they did the same thing to get their numbers), and cost you a lot fewer clams.

Personally, I went with the World S/R Torquer 305's for a couple of reasons: 1) Overall, they're better castings and have more potential; and 2) Since the car is my daily driver, I didn't want the down-time required for porting the stock heads. Other factors were not wanting to spend the money on stock heads (larger intake valves, screw-in studs, new valve springs, and porting) and risk one or both being bad, and liking the chamber design of the S/R's over the stock 416 castings.

As you can see from the sig, we're about to see what the World 305's will do on a 4" bore.

 

I built one.

But you said its just a good cruiser, why bother stroking it?? You could always do a basic 305 rebuild or get a 350 shortblock with the proper heads for it (since you want to buy heads anyway).

Or you could swap another motor in, and could keep your original motor out of the car

 

@ five7kid

are they usable out of the box or is there much work involved for a good performance gain?
Any estimated hp-numbers?

Thanks
Pat

 

Looks like my reply got lost in the outage.

I would not use the Worlds out of the box. The bowls are left with a lot of excess casting material and sharp edges.

I don't know how much difference porting them makes because I ported mine before installing. A couple of magazines had articles a few years ago about comparing a 305 TPI with 3-angle valve job stock heads vs. pocket ported World 305's on the dyno. The Worlds made almost 50 HP more. However, they never pocket ported the stock heads for that comparison.