So I can pick up a set of Trick Flow GenX 205's that are assembled with Ti Retainers for $1,200. They are "New" but were installed on an engine that never was started.

I am looking for a head that wont lose any lowend compared to my stock 243's. Current setup is a Gen 4 LMG 5.3 with a Crane 210/218 .551/.551 116LSA. With longtubes and what not. 6k RPM shift points. I tow alot and would like to gain as much performance as possible.

Would I benifit from the TF 205s or stay with the stock 243s and do some work on those.

 

If it truly is bottom end power you want then yes they will make a very nice improvement.

 

Drop your cam lsa down and your bottom end will be even better with either head.

243's have a 210cc intake port, the 205 will actually help your lowend and the associated porting will be beneficial.

 

Pat is absolutely right. A more narrow LSA combined with those heads will make a world of a difference. It'll sound cooler too

 

If your 243's are stock they are 64 cc and the trickflows are 58cc so they will up your compression which will help out quite a bit.

 

I originally had the crane 210/218 .551/.551 114+4 110ICL cam and switched to the 116+2 and it honestly seemed to have a more flat torque curve than the 114 whiched peaked earlier and didnt seem the same up to 6k. But that is just my butt dyno. The current cam has me at peak tq 407 Tq at 4900 Rpm.

Yes. Stock 243s. Regardless of the heads I go with I would like to be at 11:1 compression ratio when I am done.

I know it is a 5.3 and can not be to picky with low rpm tq but would like the most out of it. I was told a smaller intake runner will help but may not provide the same gains up to 6k, but given 5cc it shouldnt be much.

 

The trick flow heads will flow more up top too... they flow more air through a smaller runner. Thats how they will achieve greater torque while still adding power up top.

The wider LSA will pull harder up top for sure. Pat's comment was directed solely at mid to bottom end torque. If we knew you wanted to run it up to and beyond 6k the answer would have been different.

It sounds to me like the 205's are a great fit for you to be honest.

 

Appreciate the reply.

Do you think a 112LSA cam with the same specs would benefit me over the 116. Say from 2k RPM to 6k. I really dont need to rev past 6k, with the 4 speed going throughout hills it likes to be at 3500RPM the best. I pull around 6500lbs. I do not fully understand the LSA completely but from what i read that a tighter LSA (say 112+2) brings the torque curve in sooner but dies off sooner compared to my current (116+2) which broadens the torque curve and makes it more of a flat curve and can pull to 6k but wont have that early torque pull, is this correct?

I really cant pass up the deal on the heads. I thought they were a great deal. I heard Trickflow also uses Pac springs so thats a plus as well.

Any idea what going from a 64.5CC combustion chamber to the 58CC would bump my compression too. Using stock thickness gaskets and be stock at 9.9:1 compression ratio currently. I did calculate that 11:1 compression ratio would be my max with the cams specs and dynamic compression ratio of around 8.1:1. For 91 pump gas at 0-2k elevation.

This may not change much but I currently have 4.30 gears and 33's and will be swapping to 4.56's and 34's once I get my lift on the truck.

 

Not looking to highjack your thread but very close to the same situation for myself. I would grab those heads based on the fact that they will give more room to grow and the price is half off.

2006 5.3 so dished pistons, 243 heads milled 30 with a 212/218 low lift on a 114 LSA.

265/70/17 (31.5") with 3.42. Wish I had the money for 4.10's, but I am 4wd so it is pricey. Stock converter. I know these two points limit my performance greatly.

Looking for a good low end with a 5800-6K peak.

Open to a different cam, contemplated heads as well but the cost and gain I was told was not worth the small gains.