My buddy has an "06 ECSB Silverado with the 4.8. We're getting ready to put a handful of mods on it and were wondering what kind of numbers and times to expect. The mods about to go on are Texas Speed 224/224 .581/.581 on a 112 cam, supporting vavlesprings and pushrods, a set of cleaned up 241 heads, longtube headers wrapped in header wrap, tuned with HP tuners. He's already got a CAI and 2.5" true dual exhaust. Right now he has the stock stall converter, open diff, and 3.23 gears. What do y'all think?

 

Gonna need a mid to upper 3000 range converter for that cam and you guys need to mill the heads to maintain stock comprression, or mill more to bump up the compression which that cam really needs... the 241's have a bit bigger chamber than the truck heads i believe. Oh yeah, will need a diff too.

THat being said I think it has the potenital to make good power if the compression and driveline is right.

 

I hope you milled those 241's a decent amount other wise your gonna drop the CR down... That is the last thing you want todo to a 4.8 is drop the compression.

 

There will be 4.10s, LSD, and 3200 rpm stall in the future. Asking what y'all think the truck will do with the mods going on it currently. Why would the 241s drop the compression? They should raise it from 9.5:1 to 10:1

 

THe truck heads have smaller chambers than the 241's. You'd prolly need to mill alot AND thinner head gaskets to get the CR up. I agree, you don't need to loose CR.

 

I was using the info from this page to come up witht the compression being raised to 10:1. https://ls1tech.com/forums/generatio...s-details.html

 

The ls1 w 241 is a 10.0:1 motor with that bore, piston design and a 66 cc head etc. A 4.8 is 9.5:1 with a 61 cc head. Changing that to a 66cc will kill the compression.

 

yep those heads will drop the CR. it's going to feel slower then stock with a tsp224, stock converter, 3.23 gears, until like 4500rpms. sell those heads that you don't need and get a converter or gears, or BOTH.

 

I'm aware that it will feel like a dog uI'm awarentil upwards in the RPM range, but I don't think it will be that high. I can't imagine that I could get enought for them to pay for a stall and gears. I only gave $100 for them.

 

Yeah you need to mill heads to get from 66cc to 61cc I believe it is for the 706 casting (4.8/5.3head) also that open diff isn't really going to help much. On my friends single cab with a zo6 cam and 2600 stall and 3.73s and bolt ons went high 13's now its 6.0 w/heads and cam on the bottle its going mid to high 11s