11 days ago my motor blew the intake gasket. Since then it has sat while TGO has been down. *** I love this site!!! LOL!! Now that it's back up, I can search again. My motor is a Frankenstein 305/350 hybrid. The block is a 350, but has 305 heads, injectors, memcal, and exhuast. I have the 22# injectors and L98 heads by the end of the week.

Which leads me to my question. What gains should I expect going from stock Lb9 heads to stock L98 heads? Would 15-20hp/tq be about right? That's fine with me. But is there a chance that will I lose torque? I don't think I would, but I probably will with the LT's.

-OR- would the gain be only like 5hp/5tq and I should just stay with the Lb9 heads for now, and have these L98's ported and get a mean cam later on? I mean the heads will be as simple as removing the Lb9 heads, putting the gasket on, putting the L98 heads on, bolting the rockers on, and re-assembly.

 

Iron L98 heads or Aluminum?

 

Sorry, they are iron.

 

Yah, I would say 10-20 HP and your pinging problems will go away. The 305 heads are 58cc and the 350 heads are 64cc. You probably have more than 10 to 1 compression ratio right now, not good with iron heads.

 

I'd agree, easy 10-20 hp, but I'd wait and do some porting that way you see a nicer gain when you do the swap.
- When you say LT's loosing torque, you mean long tube headers? if so, then you won't loose any torque, you'll gain tq and hp.

 

Yeah I meant Long tubes. Okay, 10-20 sounds good. So with LT's and better heads, I could see 30-40hp alone from those 2 mods? I put down 187whp and 270wtq 1 year ago. That was with the exhaust unhooked after the cat and getting and a flowmaster muffler. Since then I have only added a CAI. So with the correct stock heads, LT's with full exhaust, 22lb injectors, and 350 memcal how much should I expect to hit w/o tuning? 240? Don't L98's put down like 210-220whp? So LT's and full exhaust should give me at least 20 extra whp right?