Id like my 305 TPI motor to have more power.

Here are the facts:

87' LG4 motor from/in my 87' Monte LS.
Heads: stock *high swirl* heads, same as LB9/L69 I believe.
Cam: from a 88' TPI 5 speed Firebird/TA(basically a L98 cam?).
TPI setup: stock from intake base, using 88/89 air intake elbows and a K&N filter on the end, otherwise stock.
Injectors: 19# Bosch Ford application.
Stock chip and everything else(parts unless noted from a 87' LB9 Trans Am), timing set at 6-7 degress advanced.

New cap/rotor, Delco plugs gapped at .35. Hooker emmissions legal 2050 series headers, Hooker catback exhaust system. New O2 sensor, gutted out cat(hey I needed a MCSS style cat ).
Im guessing it has 210-220 hp now. Rebuilt, improved 2004r, and stock 3.08 gears.

What Id like:

More power....I want to keep the stock motor since I dont want 300+ hp or anything. Car is a daily driver spring through fall, but not exactly a beater . 250+ hp should be fine for the motor, and Id probably want to change the gear ratio as well.

What Im thinking:

3.42 or 3.73 rear end...3.73s would be easier to find from a SS, since the 85-88's have that ratio while 83-84's have the 3.42s. Not sure if the 3.73s would be too much for the TPI? A 8.5" rear would be sweet but probably not neccissary or affordable.

Aluminum L98 heads, relatively affordable and would help out. Or some Vortec heads....or some Torquer heads. Ive seen the last 2 used with good results on 305s. Curious on opinions. Or possibly just port/polish my stock heads?

LT1 or ZZ4 cam? Seems the LT1 is the choice but some like the ZZ4 too.

Port the stock TPI intake, or leave it alone?

Also any thoughts on roller tip rockers...if they would be worth it for my application or not.

Thanks for any tips or help, hope this topic isnt beaten to death or anything...much appreciated!

 

I'd go with the World Torquers, as the L98 heads would need to be further modified to maintain compression. 1.6 Rockers would give higher lift on the L98 cam, & go full roller or go stamped. Don't bother with semi-roller. The LT1 cam is not much better than the L98 cam... not sure on the ZZ4. I think the heads and 1.6s alone will see you your desired gains, however porting out the TPI system will show you more (and you'll probably want more ) I wouldn't go higher than 3.42 for the rear.

 

ZZ4 is a nice setup. 208/221@.050 .474/.510" 112 degree seperation. It is prolly too much for the stock computer on a 305 though.

 

..... time will only tell for me!!! muahaha!!


The L98 heads hes talking about are the aluminum vette heads that have the same 58cc chamber... no loss in compression. Its a good alternative, but they arent that easy to find(at least for me) and when i do see a set that has been worked, they ask a lot. I sugest the world heads because they have a lot more area to port if need be. I think the set up i have should put me at 250hp at least. I sugest going with a 2400-2800 stall and 3.42's. Stay with 1.5 ratio. Porting out the base or buying a larger "big mouth" base would help the breathing. I think (and hope) that my combo im gunna do should put me into the low 14's/high to maybe mid 13's after im done with everything. Good luck on the build up man. Dont let people tell you the 305 isnt worth it. If you have the money and the time to make it fast, do it man!! Good luck!

 

Depending on budget, go with vortec heads and SDPC base. Better than alum L98s but will need to be worked for springs and decked. Might want to check out the LT4 production cam, 203/210 .476/.479 115lsa. I'm pretty sure lift is with 1.6 rockers.

 

My combination for a 305 is in my sig and it makes more then 300 HP, runs on 87 octane gas and idles fine with the stock chip.
I would choose either the corvette alum heads or the Vortec heads. The Corvette heads do not flow as well but you can probably build the engine for less money because you can use a cheap used corvette intake if you need to keep the EGR functional or you can use your intake by elongating the middle intake bolts and a custom chip to disable the EGR. If you run the vortec heads you will need the vortec intake manifold which is expensive, but this combination does yield excellent power. For the cam I would choose the ZZ-4, it pulls well and idles aggressively at 750 RPM. If you run the ZZ-4 cam you will have to modify both the vortec heads and corvette heads to accept the .505 exhaust lift. With the LT-1 cam the lift figures will work with the stock valve spring assemblies on the Vortec or Corvette heads. The SR heads are my least favorite head out of the three that you mentioned as far as power production is conserned but they are the easiest heads to bolt on and make work. They will bolt onto your stock intake manifold, the EGR will be functional and they will accept the .505 exhaust lift. Any one of the three heads you mentioned is substantional better then the stock heads that you are currently using.

 

I like the vortec's but... its just too much money to invest into a new intake and all new stuff... I rather just whip out the die grinder, some carbide bits and go to town!!! Id like to see a comparison of SR 305 heads vs 305 vortec's vs L98 Aluminum...

I think the SR's are better then the L98's only because the L98's are from a production car, to where the SR's havent been subjected to bean counters as the L98's have. I have heard more bad things about vortecs recently... for a while, everyone was running them... but it now seems like there dying off. I think if I went with vortecs, i might consider using the ram jet intake. The vortec you put on your car, are they the ones off the trucks? Wouldnt the chamber be large... like near 62cc? I think Ported SR's would do better then the others on a mild CR car. If I was building a high compression engine... its a no brainer... id go L98's and port them. I like the SR's out of all of them because of the out of box power. They have a jump start on the other 2 heads becuase of this, and i think the SR's can be made to flow as good as a good set of vortecs..

 

bjankuski, you know Jeremy, a guy with a blue 79' Monte near Appleton that was TPI'd at one point? . He gave me your email and told me about your combo...the reason I started asking about the Vortecs/SD intake. Thanks for the reply.

I guess Im looking at a budget and to keep it emmissions legal if it has to be. Which makes it sound like the LT1 cam might be a better fit..I dunno. Im exempt thanks to registering out of the area but would like to keep it legal anyways. Not sure if any of those combos wouldnt be.

How much is the Scroggin Dickey intake? How much for the Vortec heads, and from where(stock, aftermarket)?