I wanted to start a thread that addresses the long-standing, sometimes heated discussion on the "build up the 305" versus "install a 350" subject.

From what I have surmised with the vast knowledge and opinions I have seen exposed on this subject, it appears that there are 3 items that can be swapped over to a 350 from a modified 305.

1) Cylinder Heads-
Some aftermarket (World torq, Edle, Trick flow) and some GM cylinder heads-(ZZ4/L98 aluminum for example) can be swapped over. Better breathing heads (not to mention the weight savings of aluminum) can really wake up a 305.

Estimated Cost- New- 800-1200 (I have seen used heads on Ebay go for 1/2)

2) Headers-
SLP,Hooker 2055's, Dyno Dons- Since the headers attach to the cylinder heads, this is a straightforward swap.

Estimated Cost 700-900

3)Camshaft-
If the Cylinder heads can take the lift of the cam, then barring any ECM issues, this can also be "portable".

Estimated cost - 200

Total Cost - $1700- $2300..

Granted you can buy a NEW 350 crate for that total, but you'd have a 350 without quality heads/cam. Imagine buying a 350 crate motor for $1700 then swapping over the ZZ4 head and cam....Now you've got a 350 that probably can push 400hp/Tq...For less than a ZZ4!

The thing is, there is NO cheap way to build a 305 motor up. But if you are willing to incrementally increase the performance of your vehicle, it may be a good idea.

I think if you plan to own your vehicle for a long time and have some time AND desire to pull the engine and get the hands dirty (like me, God willing) doing a slow build up with the 305 and swap over the parts to a 350 block seems sensible to me.

I look at is as a long term/slow financial money pit drip versus a one time wham bam wallet buster way to build up some much needed performance.




Still willing to learn
Chuck

 

Also, consider this. If you were to spend $1700 on a 350 but you are still running the stock iron manifolds, well....then you cannot add $700-900 to the cost difference to a 305 buildup since you will need the aftermarket headers anyway.