thinking about going with these heads. i have a stock 305 and want to keep the 305 as the power plant. i want to put these heads.....

http://store.summitracing.com/partde...50%2D1&FROM=MG

and i want this intake.....

http://store.summitracing.com/partde...2D3704&FROM=MG

will this combo work well together and is it better then stock or would i get more out of doing work to what i have already?

with these heads will i have to change the push rods to something else and if so how do i know what to change to.... lengths, brand,etc?

any and all help is appreciated.

 

You won't have to change anything. A better cam would make it run a lot better, though.

If you want to keep center bolt valve covers, you'll have to grind off the perimeter bolt bosses. If you keep your rocker arms, you'll have to drill out the pushrod holes in the head to round (assuming yours is '88-up - you didn't say - and has self-aligning rockers).

Those heads benefit greatly from some basic port clean-up.

 

you would get similiar results by using an 081 casting cylinder head and the stock intake manifold. everything i've read shows the intake manifold on a tbi motor is not the weak link. do a search for Fast355. he's built several fast 305's that were tbi fed. mine's quick, but i'm not using tbi.

 

ok... i am really not understanding alot of this stuff... this is what i want. i want to change the heads, the intake the headers and the cam, how ever i dont want to modify anything. i want to be able to take parts off and then put parts back on. it sucks that i dont have anyone that can stand next to me to help explain some stuff. i could really use it. so with all this said is anyone willing to make me a parts list that i could use for my build. if you can just give the name of the parts i will do the looking on jegs and summitt. i will tell a little about the car.

91 rs with 121000 miles. every thing is stock except for the muffler which is a flowmaster. any thing else you need to know just ask...

i am not looking for big hp gains. just want a little more hp say around 300 or less. i want it mainly for looks and i want a nice strong sound.

some one please help.

 

are you planning on doing computer tuning? the tbi responds so poorly to mods without tuning that you can't even put a catback on it without messing with stuff. if you put a new camshaft and cylinder heads and everything, you better be prepared to do some tuning to even get it running.

 

Ok since we are talking about 305s i plan on removing my intake and puting a weiand intake single plane and a 750 carb how would that effect my 305.

 

It will reduce the low and midrange torque a lot and make the thing into a dawg.
Get a dual plane hi rise manifold.

 

yeah, that'd be the worst thing you could do for a stock 305.

put a holley street dominator intake p/n 300-36 and a holley 650 double pumper if you want good power out of the 305...that's what i'm running, but you may want to add some camshaft too.

 

get a 350?

 

How about "get real"? A 350 is hardly a remove and reinstall for TBI.

Everything I said can be removed and installed with the exception of needing to grind off the perimeter valve cover bolt bosses from the heads.

Keep the cam mild so you don't have to do any PROM tuning.

The TBI exhaust is really restrictive. You aren't going to get to 300 HP with it.

Of course, you probably won't get to 300 HP without PROM tuning, either.

 

what is "valve cover bolt bosses"?

 

From 1955 to 1986, small block Chevy valve covers had 4 bolts on the outside of the valve cover (two on each side). There was a "boss" cast into the heads along the gasket rail for those bolts. World heads have those bosses, which get in the way of the rail built into the centerbolt valve covers. If you want to reuse your centerbolt covers, you need to grind those bosses away. I suppose you could modify your valve covers, but I would think that would lead to leaks.

 

do i have to use the center bolt valve covers or could i use aftermarket? i would assume that if the bosses are there they are drilled and tapped for the bolts to use the valve covers that should go on there.. right?

 

I alway though more fuel more air would be the best ?I not saying anyones wronge but .No one on this site seems to like the single plane intakes is it the cause of the cam ,does it have to be the right combo ?i mean there right tough what better the that? But i will listen this will not happen unit the mid winter.

 

you'll want a relatively large camshaft to run a single plane intake manifold on a 305. by the time you get a cam and heads that will flow into the upper rpm range of a little motor that wants to zing, you'll have to address things like rod bolts and whatnot to hold up to the higher revs. at that point, you might as well just pull the bottom end and put in a 4" bore kit...not to mention the loose converter and tall gears required to make a 305 with a single plane work well together.

look in my garage for a 305 combo that won't cost you much and will net you some impressive gains. based on mph/weight, i'm making right at 300rwhp.

 

You could run aftermarket perimeter valve covers. The bosses are drilled & tapped.

 

so what your telling me is that the intake wouldbe over kill ,too much air coming in .The only reason i ? so much is cause i had a single plan for my L98 block and i have post that befor and every one said no way for that motor too ?

 

a single plane intake is better off for a motor that will rev to 6500+rpms, and one that normally starts making power above 3500rpms...neither the lg4, nor the l98 will do that in stock form...it's more than just too much air, but about controlling air velocity.

run the holley street dominator intake p/n 300-36. i've been running this on all my motors since i've been building sbc's, and i'm VERY pleased thus far. it has a VERY wide rpm range, from idle-7200rpms. it has fed a number of different combos, all with better than average results.