Vince98

Im at a stand still with my build at the moment i thought i had it all figured out but another forum member brought this to my attention and ive been doing some serious thinking on it.

These were the original plans for the car. 98 C5 6 speed
-Stock bottom end LS1 60k miles on current motor.
-A&A si trim
-Brian Tooley custom blower cam kit
-Comp turnin rocker arm upgrade
-New timing chain
-New oil pump
-New lifters
-ARP head studs
-LS9 head gaskets
-Alky meth injection
-Long tube headers
-Exhaust

OR

-408 long block from Texas Speed

The 408 is around $6800 for the long block only thing else i would need is a fast 102/92 and a 102/92 throttle body and maybe valve covers?

If i was to put the 408 in the car i would eventually run a 150 shot on it maybe more. Im not worried about the extra weight of the motor as im only worried about straight line performance. I like the idea of having a fully forged 408 thats brand new in the car that can hold up well to boost or juice. I would like 500RWHP out of the 408 NA.

Am i crazy for considering the 408 or should i just stick with my LS1 and run it till it pops?

Also this is not a daily driver or anything so down time means nothing to me.

redcycle13

You can make a lot more than 500whp with the A&A Kit. Then you can have all the power all the time. I got tired of filling bottles within a few months and switched to boost. It's been expensive, but fun.

winters97gt

408+SI trim+150 shot.

Vince98

The A&A kit would defiantly make more power on the 346 vs a NA 408 out of the box but I would be running it on a 60k mile stock bottom end. The 408 would stay NA for a while and then I would put a 150-300 shot on it just because that's the cheapest way to add power. A&A kit with the 408 would be awesome but that's not In the budget at the moment.

blown81bu

if i had to do it again it would be an erl aluminum sleeved block..would def not want the added weight..

alans02z

Your adding weight either way. Ive went the 408 route before, and while it was alot of fun I wasnt as happy as I am with my cammed procharged set up.

Vince98

How are the 98 ls1 blocks in durability? I no they have a different oiling system and different valve covers but what about the block itself?

I've heard the 98 blocks have thin walls and are weaker then the other ls1 blocks is this true or just a rumor?

MVP'S ZO6

The LQ9 is about 80LBs heavier than the LS1/6.

Plenty of reasons to go with a factory iron block over a their aluminum sleeved counterparts.

If you are going to go straight don't worry about the weight.

You start getting into sleeved blocks they are nice but a lot less people out there are qualified to put in sleeves properly.

For your current power goals either one isn't a bad choice. If you want a ton of room to breath and don't want to spend 6K on an aftermarket aluminum block or 3K on an aftermarket iron block then do an LQ9 block and forget about it.

robert miller

With this much power on a sleeved block if it not 110% correct one of those 8 holes will go out are give up on you for sure.

The ERL block work is great they have it down for sure but also they only use the one block in their set up, Plus that dam block goes for good $$$$.

redcycle13

I just got my sleeved block back, and I'm in it for $3200 with final honing still to be finished. Look at how much meat the sleeves have, and that's at 4.155 bore.

Vince98

If I was to buy a iron block it would a gen III short or long block from Texas speed that way I can re use everything on my current motor as far as cover etc go.

If I super charge the ls1 I'll be making around 600rwhp with a cam and meth injection and I'm not so sure how the stock internals will hold up. Or the block for that matter.

bad man Barry White

Plenty of guys in the 750-800 range on stock blocks with turbo and sc. These are a ticking time bomb but who's to say you can't dial it back to 650 for alittle more dependability. I'm in the same deciscion boat as you except with a LS3 pullout instead of the 408.

Money money money.

c5mtl

Just wondering ...why would you sleeve a 4 bolt block?

MVP'S ZO6

6 bolt.

redcycle13

The four bolt block is sufficient for my power level at 1000whp. It was also machined for 1/2 heads studs. I wanted a large displacement engine so I would not have to totally rely on boost to make good power. I wanted really good power under the curve so I don't always have to rev the crap out of it like I did with the old 347.

c5mtl

The 1/2 studs make total sense....r u thinking around copper gasket and o ringing block

redcycle13

I went with Cometic MLS gaskets, and I didn't O-ring the block. I was told the larger studs would be enough clamping force. They did advise that this was close to the recommended limit for this setup, but I've seen others push a good bit more.

c5mtl

I'm pushing way 2 much water with my setup....I always check plugs and they always look fine so I'm guessing tune is safe and I'm just at the limit of my parts...imagine I'm pushing water using c16 and meth!
Going to try ls9 gaskets cause the cometics just didn't work out also going to change from regular apr studs to custom age625 arp head studs ...they are supposed to be equal to 1/2 inch studs without the maching work....I just get myself to pull the motor and do all that machine work again to oring and 1/2 stud

realcanuk

What ! Don't tell George you are going to LS9 gaskets over the Cometics. He might have an aneurism. LS9s are just forum gospel you know.

c5mtl

What I really need is oring and copper....this way I can add a nice 100 shot.....shut some mouths up in the 10.5 class at napi with a street car