HEY guys i've been running a 355 with 305 heads on a tpi..the heads are ported and polished summit tpi cam kit slp runners, no headers yet real soon waiting for my exhaust from jegs (which is on back order)bummer, but any way anybody running a similiar set up have any hp #s.....I ordered a road dyno should be in soon then i'll find out...Then i can help johnnyph on his numbers also...see ya round.... any hp #s would be great.....

 

I dont have any HP numbers, but i can tell u that u will not get crap out of that motor with those heads and the stock exhaust.

 

I will be posting numbers on a similar test. I'm about to swap on fully modded 305 HO heads, on my L98 350, along with an LT4 hot cam and some ported intake goodies. It'll all be g-teched lol

 

LokoRS, actually, I just bought a Chevy high performance builders book, and they recommended the 305 HO heads because they have a swirl port and if you have them cut for a 1.94 intake valve it will actually outflow the aluminum L98 corvette heads. but the moment of truth will be soon, I'm swapping mine on later this month.

 

I GOTTO BE GETTING SOME REALLY GOOD HP, BECAUSE THIS THING PULLS LIKE A RAPED APE, AND WILL SMOLDER A PAIR OF 295 50 15'S. I HAVEN'T BEEN TO THE DRAG YET BUT SOON AND THE ROAD DYNO SHOULD BE IN A DAY OR SO...AND MY EXHAUST SHOULD BE HERE TOMORROW SO I'LL BE INSTALLING HEADERS AND MY CAT BACK VERY SOON......SO I'LL LET YOU GUYS KNOW...

TILL THEN SMOKEM IF YOU CAN (POSI THAT IS) LOL

 

I have no doubt that it pulls like crazy and will smoke tires, but once you get past 4000 rpms, i bet once you put that thing on a dyno will jus completley die. Putting those heads on a 350 is alright for lowend torque, but kills any chance for real HP. Dont take my word for it, ask around and do a search. Those heads WILL strangle the life out of a 350.

 

ok igot my road dyno... according to it i have 383lb of torque and 245 rwhp...thats not too shabby i think....well see what it does at the trac..still need to do my complete exhaust that will be a couple of weeks...

 

I must agree with lokors on this one, i think you can gain
~30 rwhp by changing those heads to aluminum L98 heads and getting headers.
And whoever said that swirl port heads are better is smoking some crack, ask any LO3 owner (including me) about them.

 

well, swapping on those heads will be a test. Whether they do good or bad I'll let you guys know. They are getting the hell ported out of them lol

 

what do yall think about the tbi truck 350 heads?

 

WELL GUYS THE MOTOR WAS BUILT ON A LOW BUDGET,THE HEADS CAME OFF THE 305 I HAD AND NEEDED THE MONEY TO DO THE BLOCK. FOR A MOTOR BUILT IN A BASEMENT AND BUDS ITS NOT TOO BAD I THINK........:hail: :lala:

 

a friend of mine put 305 heads on his 350 that he had in his 83 z28. he loved it, even bragged about how much better it would launch. and his top end wasn't that bad either. id have to say if you have a modded 5.7 the heads wouldn't be a good idea, ported or not. a stock 5.7 would be okay, you would definitely feel and see a difference because of it boosting your compression a little. i never tried it and would rather not, but let us know how it works out.

 

OK GUYS I JUST GOT A NEW EQUATION AND MAN DOES IT BLOW ME AWAY...I'M STILL VERIFYING THIS MATH BUT ACCORDING TO A NEW FIGURE I GOT MY CAR HAS 520LB AND 334HP.....ISN'T THAT A KICKER NOW THATS NICE.....:hail: :hail: :hail: :hail:

 

holy crap it is gettin deep in here. i8myz28, i have a suggestion, stop jerkin us off and go to the track and get some real numbers, and when it runs 15s then we will tell you that 305 heads on a 350 isnt the greatest idea in the world.

and for the rest in here, i just put aluminum L98 heads on my 305 and what a difference, modrange power and torque like never before. for a mild street motor these are a great choice. go to chevy high performance's website and see that L98 heads made more power and torque than vortec heads below 4000rpm, great match for TPI. if you want to raise compression, dont use 305 heads use the L98 heads, i got mine for 600bux ready to bolt on.

 

Just make sure they are aluminum L98 heads and not the iron ones

 

WELL B4 I DID A SET OF RUNNERS AND 373'S THE CAR DID 14.11 SO I'LL DRINK TO THAT..
:lala:

 

what was your trap speed?

 

i have to put my two cents in on this one. stock casting 305 and 350 heads have the same size runners. a 350 head will out flow a 305 head with stock valves. if you install the 1.94/1.60 valves in a 305 head, it will out flow the 350 only because the 305 heads will be bowl hogged to make room for the bigger valves. the only benefit of installing the bigger valves in the 305 head is more compression. the H. O. 305 heads have much bigger runner size than the L98 cast iron head, but smaller valves. 305 H. O. heads with the 1.94/1.60 valves, full port and polish, "D" shaped exhaust, neck down valves and a 3 angle valve job will out flow the beloved vortec head, in stock form. and this head swap is much cheaper and you get the bump in compression. i don't think the LO3 had this heads, if anyone has a casting number off of a LO3 head i can check. oh and i am not smoking any crack, at least not right now. \m/

 

I thought they were both( 083 and 081) 64cc chambers ....so how would this raise the compression ratio?


but again ...arent they alllllll 64 cc ......so they would all have thge same Compression ration ?

 

H. O. 305 heads as well as the tpi 305 heads are 58cc chambers. yes the vortecs are 64cc and the cast iron L98 are 68cc's. oh and aluminum L98 heads are 54cc's. so that's how. i'll post the casting numbers on here as soon as i get them. and we did cc'd the H. O. heads that iroclee is going to run and they came in at 60cc's after the valve job and combustion chamber unshrouding. so we then milled the heads .020'' to bring them back to about 57 to 58cc's. now that i think about it, all 305 heads are about 58 cc's to fit the smaller bore. any more questions? \m/