my 91 with 305, has 38,000 miles now on her, and im wanting to beef it up before i do entire drivetrain swap
if you had this 305 auto car with ice cold air, what would you do to get better performance?
im not wanting to get into it heads deep, just good carb, intake cam swap, headers shorty or long tubes? fuel pressure reg, stall and gear
ill be going with a blueprint 400sbc, and manual swap, but im still a year or so away from that project, im just wanting to get the most performance out of this 305 till then
if i was to swap heads, what head would you go with on the stock bottom end? if i could get up around 300hp, id be happy till i get the 400 in her

my dream machine is my car with working air conditioning, small block around 500hp, 500tq, on a 5speed with 373s, and a good sounding exhaust, i have magnaflo on stock pipes now, and sounds alright for it being a 305, but i dont want to sacrifice the ac, or any drivability
just want to get the most out the 305, even if it pops before i swap it out.....
what would you guys do, without saying ls swap
i WILL NOT ls swap, im old school and would like it kind of period correct with a 5speed (maybe stay 700r) and carb (or holley efi) and ac is a must
what would you do to get around 300 or more hp on my project #dirtyeyez #TheRazorsEdgeCamaro #TenaciousZ

 

 

If you aren't prepared to do the DIY EPROM tuning than I would leave it stock until you start your future swap. Exhaust and such will transfer over to the 400 but you'd probably want long tubes assuming your transmission utilizes hydraulic slave (T5 style fork arm will impede exhaust selection).

 

good to know, im still not sure if ill go manual, or keep it auto, the main issue is just getting more power now, without cutting into my swap budget

 

There are just too many restrictions on the LO3 to be worth it. Sure, exhaust, cam, head work, intake and DIY tuning can yield positive results, its still an engine. But your results will go farther on a better platform, as your 400 will give you. You're car looks pretty nice so I am guessing you have a decent suspension set-up? If not, suspension and brakes upgrades will go a long way when you actually start making power. The factory brakes will not suffice.

 

right now im running full kyb suspension, only need frame connectors to finish out the suspension, but the kyb stuff is just 1 step above stock, could be better, but better than factory, brakes are stock for now, with drilled/slotted rotors, but plans for willwood in the future
thanks for compliments, she was repainted in 2024, due to clear coat issues, but back to same original color, #9536PearlGunmetalMteallic

 

I'd spend the money on brake upgrades vs 305 upgrades if it were me. Especially with plans to replace the engine in another year anyway..

 

383 or 400 is a good choice, but i wouldnt go fuel injection, i'd run a 750 vacuum secondary, 700r4 with 3500 lock up stall.

But, i have done that, been where you are, wanted the vintage look, period correct, but have since let that boat go.
pulled the 383/700 and installed a 5.3/4l60---and let me tell ya, nite and day difference.

you do you, but the LS is vastly better in nearly every way.
and, 500hp? eh, 600 RWHP is much better sounding.

 

That should have been the first suspension mod.

 

You need headers and exhaust for the 400. Put that in now...it'll help that wheezy L03 a lot. Worth it.

 

I'm probably the biggest fan on TGO of building a 305, maybe the only person who supports building one. But in this case, with your immediate future plans laid out, I'd suggest you don't spend any money on the 305. Spend on chassis, big brakes and exhaust, all of which you can do now that will benefit the car in the future with a 400. You've apparently survived with the 305 for as long as you've owned the car, and another year will go by before you know it, so I'm thinking you can hold out until your 400 is ready.

I'm also a fan of a 5-speed. And if you were keeping the 305, then I'd 100% support a 5-speed swap. But behind a 400, invest in a better 5-speed, like the TKX, not a factory 5-speed. That's another thing you could do now that will also benefit the car in the future with a 400.

Believe me, I'm not a 305 hater. I stay out of 305 debates because I know nobody wants to hear someone standing up for a 305 lol. In my 22 years on TGO, I've never posted "get a 350" or the like, ever, like everyone else does. So for me to suggest NOT modifying a 305, that's a really big deal lol. Spend on upgrades now that will be necessary in the future with the larger engine. OR commit to the 305 and build the snot out of it.

 

The LS especially a pile of junk 5.3L really is not vastly superior at anything except costing more money to build and swap. If a 5.3L ran better than your 383 it was a poorly spec'd build or not tuned well. 10.5-11:1:1 383 with a decent hydraulic roller cam will make 550+ HP and 500+ TQ. 400-434 SBC will easily make 600+.

TrickFlow even just came out with a new 23* SBC head that rocks and stomps out of the box. Flows somewhere around 320 cfm out of the box from a 215cc runner. I would love to have a pair of those new TrickFlows on my 383 if only they were dual drilled for the Vortec intake pattern.

A streetable 5.3L is not making 350 whp much less 600 whp without boost. The average cammed GenIV 5.3L makes 250 whp stock and add 50-60 with a good cam. The Gen III makes even less. Both generations have cam bearing and lifter issues.

I have a Vortec 350 that makes more HP/TQ than most cammed 5.3Ls and it has a stock GM 6492 cam in it that is on the small side.

 

[QUOTE=CamaroZ_85;6581606]I'd spend the money on brake upgrades vs 305 upgrades if it were me. Especially with plans to replace the engine in another year anyway..
And I would do what you would do! Great advice. I would add to it that while I understand his wanting to keep it old school so to speak, (I'm so old school I still say the Pledge of Allegiance every morning so I get it) but man, that fuel injection tho! lol But that's doable on his 400. If I were OP and I just HAD to have 300HP for the next year I'd throw a 75hp shot of NOS on it. And it'd work on the 400sbc as well. A 75 shot is not very much and it isn't very likely to damage your engine if its installed correctly. But subframe connectors and brakes would absolutely be the better way to spend money. Tower braces maybe. Or gears. I didn't see what it currently had, but gears can make 200hp feel like 300 sometimes. And they could stay as well. I definitely wouldn't do any kind of a stall as that would need to be replaced next year probably and they kinda high. Anyway the car is sick. Clean AF, I'm jealous. Mine looks like a sack full of a-holes..

 

ive never understood the hype of the ls engines, i always said the ls is for someone who dont know how to build a sbc, or bbc
im old school, and line the old small blocks, my MCSS had a mild built 355, that i built myself, and turned 440hp/471tq at flywheel, on pump gas, and a 1406 edelbrock 600cfm, gained alot more tq after i put a dual line holley 750cfm, but never dyno after the carb upgrade, but definate noticable hp gain