Denali08

Going to put LQ9 427ci in a 2003 truck. Heads will be TFS. Truck is A4 and has stock intake/DBW TB, LT headers, 3" catback, CAI and e-fans.

Need cam and intake recommendation. Is truck intake fine to run upto 6500RPM.

Thinking of TR224 or Vindicator 240/244, since I have the two slightly used. Another option is to go custom.

1slow01Z71

iTrader: (36)

What kind of truck? 4l60e or 4l80e, what stall speed are you going to put in it? Is this a daily driver or track truck, how are you going to use it?

Denali08

4x4 Silverado 1500 RCSB stepside. It's built 4L65E, 3.73 gears. Stock stall for now. I got 3400 multi disc TC for LS1 F-body. Will use it if it fits the truck. It's DD and will see some street racing but no track.

1slow01Z71

iTrader: (36)

Id go with a FAST 92 ported setup and the vindicator cam since you already have it.

What compression ratio are you running?

How are you getting 427 cubic inches out of a 6.0 block?

budhayes3

iTrader: (19)

That's what I'm curious to know, an LQ9 is 364 cid...

1slow01Z71

iTrader: (36)

A 4.125 stroke with 4.03 bore is 421, or 4.125 stroke with 4.06 bore is 427 but thats a pretty radical setup in an iron 6.0 block, I wouldnt expect it to have a very long life.

Denali08

10.4CR. It's 4.125x4.060=427ci.

Problem with Fast intake is fitment will need alot of work. Also, DBW is another issue with throttle body!

Wonder if Edelbrock LS XT Intake Manifold will fit the bill.

Steve Bryant

iTrader: (1)

If you have not had a block machined and bought a crank, etc. I'd say stop and reconsider a 4.000" crank and a much smaller bore. Get your block sonic checked so you know where your cylinder wall thickness will be at the end of the day. The extra 19 CID is only 4.5% more displacement over a 408. Both the bore and the stroke will likely give you durability problems.

I don't mean to rain on your parade, I'm just saying stop and consider.

Steve

Denali08

Thanks for the advice. Golen Engine Service already finished the short block build for me. They sonic test each block and clearence the crank. They have built many short blocks of this type and had no problems.

I had the same concern you mentioned but was told that there is a little extra thrust wear but nothing severe that will reduce the life dramatically. Chad is a good guy to deal with and knows his stuff very well.

The price difference from 408ci is only $300. The 427ci is a torque monster compared to 408 specially with 4.125" crank.

Denali08

The engine is up and running using TR224 camshaft, truck intake and DBW throttle body and TFS215.

It made 400rwhp/450rwtq (dynojet) tuned through 4L60E. CR is 10.4. AFR is 13.

Is that low?

I know I don't have the right head/cam/intake for 427ci engine but I am looking for torque. Truck pulls hard. HP curve peaks at 5500rpm.

I am still on stock torque converter. Wonder if it will hold 450rwtq?