When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
SO i wont be able to get my heads on a bench to see how much they flow so i can get an idea of what the motor is gonna make this spring but i got some pics here of the ports of the intake and exhaust. had a valve job done. 2.02/1.60 ferra valves, seats were machined for them. heads were matched for the intake as well. supporting mods are
383 stroker
ported intake (was machined/bored out for a 58mm throttle body)
280xfi
1.65/1.6 pro magnum rockers
a/c,smog,air pump delete
cai
1 3/4 LTs to straight pipes
11.2 to 1 compression
electric water pump
373s and a yank 3400 billet converter
36 lb injectors from trickflow and 255 walbro pump
all through a 10 bolt and 4l60e
car will be tuned on a dynojet and if dyno numbers arent as high then im gonna throw some nitrous at it, bottom end is forged.
somebody give me an idea of what it could do. thank you
1.65 RR will push the lift to .624 so get a spring capable of that much lift. Might want to just stay 1:6 and use the Lunati spring kit.
XFI lifts are published using 1.6 ratio for their lift #'s vs 1.5 like other cam grinds
Assuming your heads are = to a LE2 and the tune is solid you should be in the 400RWHP/395RWTQ "neighborhood"
Im running springs good for that amount of lift. Also these heads were machined by my machinist here up in Minnesota. Lloyd did not do them. I have pictures^ to get an idea of how much was taken out.
While pictures show "something" was done....it is really a flow bench that will show how good a job the shop did in terms of performance gains....so "if" they are = to something like a LE2 than the #'s I posted should be close
I hope your springs are not Comp 918's.
FWIW I have GM heads "mildly" ported with the same Ferra valves, 383, supporting mods, etc with the smaller 466 XFI in my 383 and make 387 RWHP/395 RWTQ. This is on a 91 octane CA smog legal tune.
With the larger 467 cam, long tubes, 93 octane tune and good heads you will be over 400 HP/TQ at the wheels.
While pictures show "something" was done....it is really a flow bench that will show how good a job the shop did in terms of performance gains....so "if" they are = to something like a LE2 than the #'s I posted should be close
I hope your springs are not Comp 918's.
FWIW I have GM heads "mildly" ported with the same Ferra valves, 383, supporting mods, etc with the smaller 466 XFI in my 383 and make 387 RWHP/395 RWTQ. This is on a 91 octane CA smog legal tune.
With the larger 467 cam, long tubes, 93 octane tune and good heads you will be over 400 HP/TQ at the wheels.
I forgot what the part number on springs were but last season I had 918s but switched them out with better springs cause sometimes i hear guys talking about breaking them or valve float issues.
Heads probably arent LE2 but are atleats LE1 im sure. The goal is 400 rwhp. My heads are stock ported lt1 heads not aftermarket.
03-03-2019, 02:45 PM
Head porting and 280xfi hp numbers on 383 lt1 
