305 build?

[68post]

Ok so I took the advice you all have given me. I started looking for a 350 block. I found a short block for $125 which isn't bad I don't think. My next question is what do you all think about using 305 heads on a 350. I know it ups the compression, but how much, I think I herd somewhere it only bumps it up to like 10:1?

Suggestion for a cam. I love the lope but I want this truck to be rather quiet (daily driver) and to have more torque than I'll use pulling a trailer.

Search your head casting number until you find the combustion chamber cc size to find out if the 305 heads
s have smaller chambers or not.

The cam you picked for the 305 IS the one you want for the 350 & torque, it was at least 10* too big for the 305. You'll only want a true 9-1 compression with iron heads and a small cam especially in a truck and/or towing.
If you end-up with too much compression to the point that you have to retard the ignition timing it will be a dog.

A proper ignition advance curve will do much more for performance than even a full point of compression !

 

[TylerZ281500]

lt1 cam or similar. running one in my 355 tbi right now. you can come by them cheap and such, as for 305 heads yes its possible but measure your valves and such first. you want good flow and good compression.

 

[cviola2005]

Check the casting number on those 305 heads. I put 305 Iroc heads(58cc chambers) on a .060 over 350 with forged flattops and a 9" shaved deck. 0.028" compressed head gaskets, 11.75:1 compression.
418 HP / 450 FT/LBs

If I could do it again, I would definitely use the 305 Iroc heads again. I just wouldnt use the thin head gaskets with it. And I probably wouldn't shave the deck al the way down to 9". Maybe 9.10"

 

[Crash]

If I was you I would talk to a cam manufacturer and tell them your set up and realistic intentions for the truck. The wrong cam could ruin everything and you won't know to blame the cam or using 305 heads.

 

[TylerZ281500]

i usually talk to summit first have them recommend me a few and then contact the companies yea its a pain in the ass but it works better.

 

[Fireshaker]

Well I work in a performance shop so we have direct connections to a lot of the cam makers. I personally haven't messed with any older chevy or carb stuff. I found a short block for $75 from a friend, and I've got a location on a set of 350 heads for cheap. Should have at least a short block on the engine stand by this weekend.

 

[TylerZ281500]

make sure they arent tbi heads though. if you work at a performance shop why did you want a 305 then? just curisoity.

 

[Fireshaker]

make sure they arent tbi heads though. if you work at a performance shop why did you want a 305 then? just curisoity.

Because I had it on hand and wouldn't have to find anything except for, intake, carb, dist., and a cam.

 

[TylerZ281500]

yea but something on hand isnt always best route, your losing economy and performance with a 305 working at a performance shop id think thatd be a known concept

 

[Fireshaker]

yea but something on hand isnt always best route, your losing economy and performance with a 305 working at a performance shop id think thatd be a known concept

True but I really wasn't looking to make a ton of power or get good gas mileage. I was wanting better than I have, for as cheap as possible. Don't get me wrong when I first saw the truck, a 350 Chevy was my first thought. Normally I won't even consider the 305. How ever I had it and it is complete.

I picked up the block, and rotating assembly last night. Found out it is a 355, which may turn into a 360 depending on what the machine shop says. I've got a location on a set of heads for $75.