Heya all, i have a few quick questions.

Now this is all theoretical, (i have a 355 in the machine shop as we speak) but a friend and i were sitting around discussing engines as we usually do, and the idea came up about putting some a of the heads i have laying around on a 305, as well as an intake and carb, all off of a 350, all stock parts.

The heads are 462624s(75-86 350/400, 1.94in/1.5ex, 76cc), now with the size of that compression chamber im thinkin that the 305 would be so low on compression that it wouldnt run to par, and the swap effort would be lost in vein, im also pretty sure the carb/intake wouldnt flood the engine, but maybe.


So basicly what i am askin is, would the 305 have enough compression to make it worth the swap, as well as would the engine be flooded by the carb/intake combo. And the almighty important question of all, how much for power? Oh, and what about that combo of heads/carb/intake on that 355 being built while i can save up for some vortecs.


Thanks in advance,
Curt

 

76cc is way too much for a 305. You'd have something like 7 to 1 compression ratio

BUT, take those 305 heads (as long as they are 081, 416 or 601 castings) and port and polish them. Then enlarge the intake valve to 1.94" and you will have better than Vortec flow!

Follow the link at the end of my sig to find out how

 

what are the stock intake valve on a 1986 305 tpi lb9 ,,can i go to 1.94 thanks

 

Mikobu,

Your LB9 probably has 14014416 head castings. Those came from the factory with 1.84/1.50 valves. If you replace the intake valves with 1.94" versions, you should still remove ths exhaust valves. When the bowls above the intakes are ported (a little wider and higher/deeper), you should also bowl port the exhaust side. Get out your handy die grinder and cut down the stem guide protrusions into all the valve bowls, reduce the "hump" of material at both the intake and exhaust runner short side (increase the radius) and open the ports on both sides to match the gasket openings. Blend all the porting work with the grinder, polish the exhaust sides, and clear away obstructions (shrouding) around the outer sides of the intake valves.

The Bull has a very good set of instructions on exactly how to perform all this work in his link. Visit it, bookmark it, print it, and refer to it often.

 

1.84".

Yes, you can enlarge them.

And everything Vader says

 

how much should all of that cost ,the labour i can do but for the rest of the stuff, also what kind of performance should i see remeber i am going to change the cam also ,i think i will go to the comp 212 -218 thanks

 

Go here and read through the entire thread. It answers all your questions: https://www.thirdgen.org/techbb2/sho...hreadid=117410

 

thanks bull

 

Hey, no problemos