I am getting a pair of L98 heads for dirt cheap and I'll use them in the future. But for now, I was wondering if I would be able to bolt them up to a 305 and if it would be beneficial.

Please don't bash me trying to build up a 305, its just a temporary motor. Any imput would be appreciated.

Dan

 

Those L98 heads had better not come from Jeremy! Or you and I will have words Dan.

I've been egging him for those heads for months now, and he STILL hasn't dug them out.

Just wanted to say that. ^_^

You getting them from posbird87?

 

What you'll pick up in flow from the larger valves, you'll lose in compression ratio from the larger CC's...save the heads, port them in your free time and use them accordingly.

Even if your able to gain a few HP with them, it's way too much hassle for the swap to expect anything.

 

hmmm.... or me getting the run around by a middle man marking up prices.

 

I'll be building a motor shortly that is somewhat similar to what you want to do. The main difference is that I'm using a L03 donor for the block instead of a LB9 donor and I'm not looking for high performance. The L98 heads will bolt on the 305 block, but there are some concerns about performance and reliability. First the concerns about performance, the L98 iron heads found in the F-Bodies have 64cc chambers compared to the stock 58cc chambers in the LB9 heads. Like 8Mike9 said, you will lower the compression ratio if you just slapped them on. And considering the LB9 already has a somewhat low compression ratio, its possible that this will cause a noticable difference in power (noticably lower). There are things you can do to remedy this like run a different gasket set or mill the heads a bit but then you might find this being less and less of a budget project. Another option could be using the aluminum L98 heads found on the Corvettes. These heads have 58cc chambers and will lessen the possible issues of losing too much compression. Then there are concerns about reliability, mainly valve edge clearance and shrouding caused by the different bore sizes (3.75" vs 4.0"). From my understanding there would be no valve clearance problems as long as the valves are 1.94 intake and 1.60 exhaust, which the L98 heads are. But your cam choice here will be very important as the wrong cam can cause you issues. Commonly used cams for the budget project would be the stock L98 cam, a LT1 cam or a ZZ4 cam. Alot of these things are somewhat undocumented as this type of buildup is generally concerned a waste of time. But I say it all depends on the situation. What might be a waste of time for some can be usefull for others. I know that L98 heads on a 305 block will work with the right setup (both Willie and Saturn5 have done this) and if you talk to people who have done it (send them a PM) they might share some tips with you.

My situation is, I have a bunch of parts left over from multiple projects and I want to put them to use instead of selling them, or in some cases, giving them away. My plan is to use these parts in a S-10 truck so I can tow my Camaro to the tracks. I have an 89 L03 motor out of my 89 Camaro RS taking up space in the garage. This is commonly refered to as the 'boat anchor' motor (hahah! toss it overboard!), but I see more uses for it than keeping my boats from floating away. I also have some stock L98 parts from a 89 IROC L98 motor sitting in a box next to the 89 L03. Stock L98 heads, stock L98 cam, and the complete 89 MAF TPI setup including the computer. Finally I have a 700r4 tranny left over that will mate up to the 305 motor, and a Painless Standalone wiring harness for 165 ECM MAF TPI setups that I happened to get for free when I bought the 89 IROC L98 motor. I also have the ability to burn my own PROMs so I know I can tune any setup with enough time invested. I plan to put all these parts together and make a wannabe LB9 motor with 4 speed overdrive tranny. The donor vehicle I plan to swap this into is a 1992 Chevy S-10 regular cab shortbed pickup truck. The truck is for sale for $500 with a blown head gasket (4 banger). I plan to get the V8 conversion kit for under $400 (this includes the radiator, motor mounts, and headers). Then the only parts I'll need are the rearend and custom length driveshaft. I'm hoping I can find a suitable rearend in the junkyard and get the driveshaft made locally. I estimate the complete project to run me $3000 including the truck, all the engine/drivetrain, redone suspension, redone interior, and new paint. Final product will be a TPI powered 92 Chevy S10, black with a 3/4 drop and 16" IROC Wheels. It should make a great truck for daily driving and towing. And the extremely low compression means I can run the lowest octane, cheapest gas out there.

 

I have to tell ya, the first step to getting those heads would be to put the cash in his hands

May the best man have the heads.